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Azari-Nasab, T., CH Ghobadi, B. Azarm i M. Majidzadeh. "Triple-band operation achievement via multi-input multi-output antenna for wireless communication system applications". International Journal of Microwave and Wireless Technologies 12, nr 3 (10.10.2019): 259–66. http://dx.doi.org/10.1017/s1759078719001302.
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AbstractA multi-input multi-output (MIMO) antenna is designed and discussed for multi-band applications. The constituent antennas are composed of four L-shaped elements and a ground plane. When placed beside each other to form a MIMO antenna, a T-bar shaped parasitic structure is also embedded between the antennas on the backside of the substrate to increase the inter-element isolation. The triple-band performance of the antenna is observed at 2.15–2.73 GHz, 3.1–3.9 GHz, and 5.04–6 GHz. The isolation level of more than 20 is seen over the operating frequency range. The fabricated prototype of the MIMO antenna size is very compact (20 × 40 mm), printed on the FR4 substrate. Based on simulation and experimental results, the proposed design is useful for WiMAX and WLAN applications.
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Zheng, Zi Wei. "Iterative Channel Estimation Scheme for the WLAN Systems with the Multiple-Antenna Receivers". Advanced Engineering Forum 6-7 (wrzesień 2012): 871–75. http://dx.doi.org/10.4028/www.scientific.net/aef.6-7.871.
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Alleviate the multipath delay spread and suitable for broadband transmission efficiency, orthogonal frequency division multiplexing wireless local area network (WLAN) is widely used to assist inverse fast Fourier transform and fast Fourier transform operation domain. Orthogonal frequency division multiplexing is a blow to the broadcast channel multipath fading and high data throughput, transmission, wireless fading channel method, which is widely used to support high performance bandwidth-efficient wireless multimedia services. Several times in the transmitter and receiver antenna technology allows data transfer rate and spectrum efficiency and the use of multiple transmit antennas and multiple receive antennas through spatial processing. High-precision channel estimation scheme is very important wideband multi-carrier orthogonal frequency complex WLAN systems use multiple antenna receiver based division of labor and the overall multi-carrier orthogonal frequency multiplexing division of performance-based WLAN system is to crucial antenna to receive the symbol error rate. In this article, the iterative channel estimation scheme proposed multi-carrier orthogonal frequency division multiplexed using multiple antennas receiver-based WLAN system.
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Arun, Henridass, i Gulam Nabi Alsath M. "CPW fed circularly polarized wideband pie-shaped monopole antenna for multi-antenna techniques". COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, nr 6 (5.11.2018): 2109–21. http://dx.doi.org/10.1108/compel-12-2017-0515.
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Purpose This paper aims to present the design and implementation of a circularly polarized co-planar waveguide (CPW) fed wideband pie-shaped monopole antenna for multi-antenna techniques. Multi-antenna techniques are promising solutions for higher data rate and enhanced reliability of wireless applications. They find numerous applications in 4G/5G networks and in most wireless standards such as wireless local area networks (WLAN), wireless fidelity and worldwide interoperability for microwave access systems to enhance the channel capacity without additional spectrum by means of multi-path propagation techniques. Design/methodology/approach The antenna is designed to operate at three WLAN frequency bands of 4.8, 5.2 and 5.8 GHz. The measured 10 dB impedance bandwidth of the proposed antenna element is 1.2 GHz (24.23 per cent). The proposed CPW fed, pie-shaped monopole antenna has a gain of 5.4 dB and an efficiency of 72.8 per cent at 4.8 GHz. Findings To use the proposed antenna in a multi-antenna environment, the antennas have to be placed in a close proximity to each other. The close proximity introduces strong mutual coupling between the antennas, which in turn degrades the performance of multi-antenna systems. A multi-antenna system with two antenna elements has been constructed with an edge to edge spacing of 0.24 λ0 (15 mm), and the mutual coupling level is −17 dB. To enhance the isolation between the antenna elements, a shorting pin-based interconnected semicircles enclosed decoupling structure is proposed, which improves the isolation by a factor of 12.67 dB at 4.8 GHz. Originality/value To validate the performance of the proposed multi-antenna in working environment, the performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG) and total active reflection coefficient (TARC) are computed for the proposed multiple-input multiple-output (MIMO) antenna. The ECC value is 0.000366 at center frequency and below 0.09 for the entire operating bandwidth, which is well below the acceptable level of 0.5 as per 3GPP standard. The DG value lies above 9.5 dB for the entire operating bandwidths and it is well above the minimum value of 3 dB. The TARC values are calculated based on S parameters, and it proves that the proposed antenna a good candidate for the multi-antenna systems.
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Zeng, Wenxin, Wei Wang i Sameer Sonkusale. "Temperature Sensing Shape Morphing Antenna (ShMoA)". Micromachines 13, nr 10 (4.10.2022): 1673. http://dx.doi.org/10.3390/mi13101673.
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Devices that can morph their functions on demand provide a rich yet unexplored paradigm for the next generation of electronic devices and sensors. For example, an antenna that can morph its shape can be used to adapt communication to different wireless standards or improve wireless signal reception. We utilize temperature-sensitive shape memory alloys (SMA) to realize a shape morphing antenna (ShMoA). In the designed architecture, multiple conjoined shape memory alloy sections form the antenna. The shape morphing of this antenna is achieved through temperature control. Different temperature threshold levels are used for programming the shape. Besides its conventional use for RF applications, ShMoA can serve as a multi-level temperature sensor, analogous to thermoreceptors in an insect antenna. ShMoA essentially combines the function of temperature sensing, embedded computing for detection of threshold crossings, and radio frequency readout, all in the single construct of a shape-morphing antenna (ShMoA) without the need for any battery or peripheral electronics. The ShMoA can be employed as bio-inspired wireless temperature sensing antennae on mobile robotic flies, insects, drones and other robots. It can also be deployed as programmable antennas for multi-standard wireless communication.
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Wang, Huan, i Jian Zhou. "Brief Analysis of MIMO Channel and Antenna". Advanced Materials Research 912-914 (kwiecień 2014): 952–55. http://dx.doi.org/10.4028/www.scientific.net/amr.912-914.952.
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MIMO (Multi-input Multi-output) is an abstract mathematical model used to describe the multi-antenna wireless communication system. the transmitter can use a plurality of separate antennas transmit signals simultaneously. This paper first analyzes MIMO physical model, and then the MIMO channel characteristics and capacity for analysis, analysis of MIMO antenna characteristics and finally focus on the correlation coefficient
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Moradikordalivand, Alishir, Chee Yen Leow, Tharek Abd Rahman, Sepideh Ebrahimi i Tien Han Chua. "Wideband MIMO antenna system with dual polarization for WiFi and LTE applications". International Journal of Microwave and Wireless Technologies 8, nr 3 (4.03.2015): 643–50. http://dx.doi.org/10.1017/s175907871500032x.
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In this paper a wideband multi-input multi-output (MIMO) antenna system for WiFi-LTE wireless access point (WAP) application is proposed. The MIMO antenna system consists of two common element microstrip-fed monopole antennas with dual polarization. Physically closed integration of MIMO antenna elements requires a special technique to increase the isolation between the antennas. A novel structure of parasitic element is introduced to improve the isolation between the antennas. The proposed MIMO antenna system is simulated and optimized using CST Microwave Studio. The designed antenna system is fabricated and measured to verify the simulation results. Reflection coefficient of less than −10 dB and isolation more than 15 dB are achieved in the operating frequency range of 2.3–2.9 GHz which covers WiFi 2.4 GHz and LTE 2.6 GHz bands. The proposed system also provides dual polarization with 10 dB polarization diversity gain and envelope correlation coefficient less than 0.15. Each individual antenna has a gain of 5.1 dB and 68% efficiency.
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Pandey, Shraddha, i Pankaj Vyas. "Review of Reconfigurable Microstrip Patch antenna for Wireless Application". International Journal on Recent and Innovation Trends in Computing and Communication 7, nr 6 (22.06.2019): 25–28. http://dx.doi.org/10.17762/ijritcc.v7i6.5317.
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In recent time, world have seen a rapid growth in wireless communication. Development in antenna from single band to dual band and multi band had made the antenna system more compact. A frequency reconfigurable microstrip antenna using a PIN diode for multiband operation is using many application and hot research area. In this paper, reconfigurable microstrip patch antennas and their types like frequency, polarization, radiation pattern and gain are described.
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Chaudhary, Abhay. "Utilizing ultra-wideband with wireless telecommunications applications microstrip". International Journal of Advances in Applied Sciences 10, nr 4 (1.12.2021): 283. http://dx.doi.org/10.11591/ijaas.v10.i4.pp283-287.
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<p>The small aspect, as well as low margins of the microstrip chip amplifier (MPA) is being used in a contact system. For the last few times within the last year's research, the majority of work with MPA has been centered towards designing the portable antenna design. Wireless networking systems may be fitted with a new ultrawideband digital monopoly antenna. Throughout this exponentially changing environment, and dual multi-standard antennas play a crucial role in the implementation of cell towers. This paper presents the nature of an ultra-wideband (UWB)-based antenna array for the shape of a substratum, feeding strategies or openings.</p>
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Castel, Thijs, Patrick Van Torre, Emmeric Tanghe, Sam Agneessens, Günter Vermeeren, Wout Joseph i Hendrik Rogier. "Improved Reception of In-Body Signals by Means of a Wearable Multi-Antenna System". International Journal of Antennas and Propagation 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/328375.
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High data-rate wireless communication for in-body human implants is mainly performed in the 402–405 MHz Medical Implant Communication System band and the 2.45 GHz Industrial, Scientific and Medical band. The latter band offers larger bandwidth, enabling high-resolution live video transmission. Although in-body signal attenuation is larger, at least 29 dB more power may be transmitted in this band and the antenna efficiency for compact antennas at 2.45 GHz is also up to 10 times higher. Moreover, at the receive side, one can exploit the large surface provided by a garment by deploying multiple compact highly efficient wearable antennas, capturing the signals transmitted by the implant directly at the body surface, yielding stronger signals and reducing interference. In this paper, we implement a reliable 3.5 Mbps wearable textile multi-antenna system suitable for integration into a jacket worn by a patient, and evaluate its potential to improve the In-to-Out Body wireless link reliability by means of spatial receive diversity in a standardized measurement setup. We derive the optimal distribution and the minimum number of on-body antennas required to ensure signal levels that are large enough for real-time wireless endoscopy-capsule applications, at varying positions and orientations of the implant in the human body.
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Praveena, S., i Sunakar Prusty. "Frequency Reconfigurable Antenna using PIN Diodes". International Journal of Engineering and Advanced Technology 9, nr 1s5 (30.12.2019): 66–70. http://dx.doi.org/10.35940/ijeat.a1019.1291s519.
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With the increase in wireless applications, there is a need for compact antennas that adapt their behavior with changing system requirements or environmental conditions. Here adapt implies the antenna should be able to alter operating frequencies, impedance bandwidths, polarizations, radiation patterns. These all features are provided by the “Reconfigurable antenna”. The important feature of reconfigurable antenna is that, they provide the same throughput as a multi-antenna system. A compact frequency reconfigurable antenna is designed with the aid of Ansoft HFSS that provides multiple frequency bands. This is achieved by using electrical switches such as PIN diodes. Depending on state of switches different operating frequencies are obtained. The switches placed on the antenna elements are powered wirelessly by the antenna itself. The design, geometries and simulation results of a frequency reconfigurable antenna are presented in this report. Further advancements are to be done for this structure to achieve polarization and radiation pattern re-configurability.
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V.Prashanth, K., N. Sai Venkatesh, B. Umamaheswari, M. Mukesh, G. Praneeth, B. Ramya Latha i Syed Shameem. "Design of UWB Antenna With Multi slot for Wireless Communication". International Journal of Engineering & Technology 7, nr 2.7 (18.03.2018): 507. http://dx.doi.org/10.14419/ijet.v7i2.7.10872.
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A Compact dual slot ultra-wide band (UWB) Antenna for WLAN and X-Band applications is proposed. The projected antenna is designed for the planar ultra-wide band (UWB) antenna and ultra-wide band (UWB) with two band dismissals. The proposed antenna overall size is 30x40x1.6. The antenna comprises of Rectangular patch imprinted on the Flame Resistant (FR4) substrate with 50Ω input impedance. FR-4 is a composite material made out of fiberglass fabric woven with an epoxy pitch cover that is fire safe (self-dousing). "FR" implies fire resistant, and means that the material meets the standard. This patch consists of dual slot one for WLAN and one for X-band Satellite Communication System. The antenna intended with return loss (RL) >= 10db and frequency ranges between 3.1 to 10.6 GHz with VSWR<2. The antenna works for the applications of wireless local area network (WLAN) system (5.15 – 5.825 GHz), X-band downlink (7.25 - 7.75). The ultra-wide band frequency range for these wireless systems causes interference. To reduce the interference, band notching is done. The WLAN and X-Band satellite communication system bands are forbidden by inserting slots in the patch. The proposed antenna is having high gain at the pass bands while a sharp drop at the forbidden bands.
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Rahi, Kareem Dhahir, Leana Jabble Taklef i Musa H. Wali. "Enhancement isolation antenna to multi-port for wireless communication". Open Engineering 12, nr 1 (1.01.2022): 866–77. http://dx.doi.org/10.1515/eng-2022-0348.
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Abstract Currently, there is a rapid increase in demand for the transmission of large amount of data with extreme accuracy, which is usually performed by the antenna system. Therefore, this work aims to design an antenna system that has the potential of improving the performance of such system in terms of reducing the antenna size, and expanding the bandwidth. First, a single-port antenna was designed after calculating the basic requirements and then a comprehensive analysis of the antenna performance was carried out to reach optimum performance. Then, the antenna was connected to two, three, and four ports. Such connection was implemented while maintaining efficiency and magnification in each case within the range for wireless applications. The antenna with four input ports was designed with a 45° angle on a circular circumference around the antenna to prevent interference between the ports. The modified antenna was designed to accommodate wireless communication applications (such as the 5G mobile communications network as well as the future 6G mobile communications network). The experimental results were compared with those obtained from the simulation studio Computer Simulation Technology, which is more compatible with the practical results.
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Dilli, Ravilla. "Design and Feasibility Verification of 6G Wireless Communication Systems with State of the Art Technologies". International Journal of Wireless Information Networks 29, nr 1 (28.12.2021): 93–117. http://dx.doi.org/10.1007/s10776-021-00546-3.
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AbstractFrequencies above 100 GHz are the promising frequency bands for 6G wireless communication systems because of the abundant unexplored and unused spectrum. The increasing global demand for ultra-high spectral efficiencies, data rates, speeds and bandwidths in next-generation wireless networks motivates the exploration of peak capabilities of massive MIMO (Multi–Input–Multi–Output) wireless access technology at THz bands (0.1–10 THz). The smaller wavelengths (order of microns) of these frequencies give an advantage of making high gain antennas with smaller physical dimensions and allows massive spatial multiplexing. This paper presents the design of ultra-massive MIMO (ultra-mMIMO) hybrid beamforming system for multi users and its feasibility to function at THz frequency bands. The functionality of the proposed system is verified at higher order modulation schemes to achieve higher spectral efficiencies using performance metrics that includes error vector magnitude, symbol constellations, and antenna array radiation beams. The performance results suggest to use a particular mMIMO antenna configuration based on number of independent data streams per user and strongly recommended to use higher number of data streams per user in order to achieve higher throughputs that satisfy the needs of 6G wireless systems. Also the performance of the proposed system at 0.14 THz is compared with mmWave systems that operate at 28 GHz and 73 GHz bands to justify the feasibility of the proposed work.
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Wong, Hang, Wei Lin, Laure Huitema i Eric Arnaud. "Multi-Polarization Reconfigurable Antenna for Wireless Biomedical System". IEEE Transactions on Biomedical Circuits and Systems 11, nr 3 (czerwiec 2017): 652–60. http://dx.doi.org/10.1109/tbcas.2016.2636872.
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Wassie, Dereje Assefa, Ignacio Rodriguez, Gilberto Berardinelli, Fernando M. L. Tavares, Troels B. Sorensen, Thomas L. Hansen i Preben Mogensen. "An Agile Multi-Node Multi-Antenna Wireless Channel Sounding System". IEEE Access 7 (2019): 17503–16. http://dx.doi.org/10.1109/access.2019.2895412.
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Hidayat, M. Reza, Reza Agung Permana i Susanto Sambasri. "Konversi Antena Mimo 2x2 Frekuensi 2,4 Ghz Menjadi 5,5 Ghz Menggunakan Patch Bowtie Berbasis Dual Slot Segi Empat dan Single Slot Segitiga". TELKA - Telekomunikasi Elektronika Komputasi dan Kontrol 7, nr 2 (22.11.2021): 161–73. http://dx.doi.org/10.15575/telka.v7n2.161-173.
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Perkembangan antena radar semakin cepat dan beragam, salah satunya adalah antena MIMO (multiple output). Antena MIMO banyak digunakan untuk teknologi 5G karena efisiensi spectral dan fekuensi yang tinggi. Antena MIMO juga merupakan suatu sistem yang menggunakan multi antena baik pengrim (Transmitter) maupun penerima (receiver) yang bisa mengatasi kelemahan pada sistem komunikasi wireless. Penelitian ini merancang sebuah antena mikrostrip MIMO 2X2 dengan menggunakan patch bowtie untuk mengkonversi frekuensi dari 2,4 GHz menjadi 5,5 GHz dengan menambahkan dual slot segiempat dan single slot segitiga. Hasil simulasi menunjukkan penambahan dual slot segiempat dan single slot segitiga pada patch antena bowtie dapat menggeser frekuensi kerja dari 2,4 GHz menjadi 5,5 GHz. Dari hasil simulasi antena MIMO 2X2 didapatkan nilai return loss S11 sebesar -46,5 dB, insertion loss S21 sebesar -25,2 dB, bandwidth sebesar 192,2 MHz, VSWR sebesar 1,00 dan gain sebesar 3,11 dBi. Hasil dari pengukuran antena MIMO menunjukkan perbedaan dari parameter antena 1 dan 2. Hal ini disebabkan adanya ketidaksamaan ukuran dari antena 1 dan antena 2. Pengukuran nilai return loss untuk antena 1 yaitu sebesar -22,32 dB dan -15,63 dB untuk antena 2. Hasil pengukuran insertion loss antena 1 dan 2 memiliki nilai yang sama yaitu -43,5 dB dan untuk lebar bandwidth memiliki perbedaan nilai yaitu 50 MHz untuk antena 1 dan 100 MHz untuk antena 2. Pengukuran nilai VSWR 1 didapatkan nilai sebesar 1,96, VSWR 2 sebesar 1,41. The development of radar antennas is getting faster and more diverse, one of which is the MIMO (multiple output) antenna. MIMO antennas are widely used for 5G technology because of their high spectral efficiency and frequency. MIMO antenna is also a system that uses multiple antennas, both transmitter and receiver which can solving the weaknesses in wireless communication systems. The research designed a 2X2 MIMO microstrip antenna using a patch bowtie to convert the frequency from 2.4 GHZ to 5.5 GHz by adding dual rectangular slots and single triangular slots. The simulation results show that the addition of dual rectangular slots and single triangular slots on the patch bowtie antenna can shift the working frequency from 2.4 GHz to 5.5 GHz. From the simulation results of MIMO 2X2 antenna, the return loss value of S11 is -46.5 dB, insertion loss S21 is -25.2 dB, bandwidth is 192.2 MHz, VSWR is 1.00 and gain is 3.11 dBi. The results of the MIMO antenna measurements show differences in the parameters of antennas 1 and 2. This is due to the difference size of antenna 1 and antenna 2. The measurement of the return loss value for antenna 1 is -22.32 dB and -15.63 dB for antenna 2 The results of the insertion loss measurements for antennas 1 and 2 have the same value, which is -43.5 dB and for the width of the bandwidth has a different value, 50 MHz for antenna 1 and 100 MHz for antenna 2. Measurement of the value of VSWR 1 obtained a value of 1.96, VSWR 2 is 1.41.
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T. G., Shivapanchakshari, i H. S. Aravinda. "PSO-CCO_MIMO-SA: A particle swarm optimization based channel capacity optimzation for MIMO system incorporated with smart antenna". International Journal of Electrical and Computer Engineering (IJECE) 10, nr 6 (1.12.2020): 6276. http://dx.doi.org/10.11591/ijece.v10i6.pp6276-6282.
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With the radio channels physical limits, achieving higher data rate in the multi-channel systems is been a biggest concern. Hence, various spatial domain techniques have been introduced by incorporating array of antenna elements (i.e., smart antenna) in recent past for the channel limit expansion in mobile communication antennas. These smart antennas help to yield the improved array gain or bearm forming gain and hence by power efficiency enhanmaent in the channel and antenna range expansion. The use of smart antenna leads to spatial diversity and minimizes the fading effect and improves link reliability. However, in the process of antenna design, the proper channel modelling is is biggest concern which affect the wireless system performance. The recent works of MIMO design systems have discussed the issues in number of antenna selection which suggests that optimization of MIMO channel capacity is required. Hence, a Particle Swarm Optimization based channel capacity optimzation for MIMO system incorporated with smart antenna is introduced in this paper. From the outcomes it is been found that the proposed PSO based MIMO system achieves better convergenece speed which results in better channel capacity.
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Muttair, Karrar Shakir, Ali Zuhair Ghazi Zahid, Oras Ahmed Shareef, Raed Hameed Chyad Alfilh, Ahmed Mohammed Qasim Kamil i Mahmood Farhan Mosleh. "Design and analysis of wide and multi-bands multi-input multi-output antenna for 5G communications". Indonesian Journal of Electrical Engineering and Computer Science 26, nr 2 (1.05.2022): 903. http://dx.doi.org/10.11591/ijeecs.v26.i2.pp903-914.
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A <span>good antenna design has played an essential role in the design of wireless communication systems, international companies are looking for the best design that suits their products in terms of size, bandwidth, gain, cost, and performance. In this paper, three antenna models are designed for fifth-generation (5G) communications, the first model is a single antenna, the second model is a two-ports multi-input multi-output (MIMO) antenna, and the third model is a four-ports MIMO antenna. The geometric dimensions of a single antenna are 20×37×1.6 mm<sup>3</sup>, the two-ports antenna dimensions are 44×37×1.6 mm<sup>3</sup>, while the four-ports antenna dimensions are 74×44×1.6 mm<sup>3</sup>. The design of these antennas was based on the latest strategies in terms of their small sizes and operating from 13.5 to 20 GHz in wide and multiple bands to be compatible with all advanced communication devices. Based on the results that emerged, it was noted that the reflection coefficient (S11) < -10 dB and has better isolation between the ports is < -26 dB. While the envelope correlation coefficient (ECC) value is < 1.036×10<sup>-9</sup>, and the diversity gain (DG) value is 10 dB. All antennas proposed operate in ultra-wideband (UWB) which is very necessary for 5G communications devices.</span>
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Bang, Inkyu, Hyunwoo Nam, Woohyuk Chang, Taehoon Kim, Jong-Myung Woo, Choul-Young Kim, Tae-Won Ban, Pangun Park i Bang Jung. "Channel Measurement and Feasibility Test for Wireless Avionics Intra-Communications". Sensors 19, nr 6 (14.03.2019): 1294. http://dx.doi.org/10.3390/s19061294.
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Wireless avionics intra-communication (WAIC) refers to a wireless communication system among electronic components (e.g., sensors and actuators) that are integrated or installed in an aircraft and it is proposed to replace heavy and expensive wired communication cables. Recently, the use of a frequency band (4.2–4.4 GHz) for the WAIC (so-called, WAIC band) has been approved by international telecommunication union (ITU). Accordingly, several existing wireless protocols such as IEEE 802.11 and IEEE 802.15 are being considered as candidate techniques for the intra-avionics sensor network. In this paper, we perform a real field experiment to investigate wireless channel characteristics in intra-avionics sensor networks at the WAIC bands by a software-defined radio platform (universal software radio peripheral, USRP) and self-produced monopole antennas for the WAIC band. Through the experiment, we validated the feasibility of IEEE 802.11 protocol for the intra-avionics sensor network at the WAIC band in real aircraft environments. Furthermore, based on the measurement data, we evaluated the bit error rate (BER) performance of multiple antenna techniques where we considered the maximum ratio combining (MRC) for the multi-antenna receiver and the space-time block coding (STBC) for the multi-antenna transmitter.
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Zheng, Zi Wei. "Frame Synchronization for the DTMB Systems with the Multiple-Antenna Receivers". Advanced Engineering Forum 6-7 (wrzesień 2012): 434–38. http://dx.doi.org/10.4028/www.scientific.net/aef.6-7.434.
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Faced with the challenges of modern communication, high data throughput requirements, extensive research has been paid to broadband modulation. The multi-carrier modulation is one of the most important wide band modulation techniques. Orthogonal frequency division multiplexing (OFDM) is an effective blow to the broadcast channel multipath fading and high bit rate transmission multi-carrier modulation technology of wireless channels, it is widely used in modern digital television terrestrial broadcasting (DTTB) system to support performance bandwidth-efficient multimedia services with the aid of inverse fast Fourier transform and fast Fourier transform operation. Multiple-antenna transmitter and receiver technology allows several times to achieve data transmission rates and spectrum efficiency and the use of multiple transmit antennas and multiple receive antennas through spatial processing. The Digital Terrestrial Multimedia Broadcasting (DTMB) system with the multiple-antenna receiver is considered in this paper. Digital Terrestrial Multimedia Broadcasting (DTMB) has three kinds of Frame Head mode with PN420/PN595/PN945 as training sequences for the time domain synchronous OFDM (TDS-OFDM). At the receiver side with multiple antennas, Frame Head mode detection should be done. In this paper, the frame synchronization scheme is proposed for the DTMB systems with the multiple-antenna receiver. System performance studies under different channel situations are used to verify the efficiency of the proposed scheme for the DTMB systems with the multiple-antenna receiver.
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Dahrouj, Hayssam, i Wei Yu. "Coordinated beamforming for the multicell multi-antenna wireless system". IEEE Transactions on Wireless Communications 9, nr 5 (maj 2010): 1748–59. http://dx.doi.org/10.1109/twc.2010.05.090936.
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Gupta, Manisha, i Vinita Mathur. "Hexagonal Fractal Antenna using Koch for Wireless Applications". Frequenz 72, nr 9-10 (28.08.2018): 443–53. http://dx.doi.org/10.1515/freq-2017-0203.
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Abstract This paper presents the design, fabrication, and measurement of a novel ultra-wideband (UWB) hexagonal fractal patch antenna. This antenna uses hexagonal shape with Koch snowflake fractal at its edges. The proposed antenna has been excited using microstrip feed. The measured result of this antenna offers the ultra wideband characteristics from 3.265 GHz to 8.2 GHz. The antenna is practically fabricated and tested. Measured results show a good agreement with simulated results. The measured radiation patterns of this antenna are nearly omnidirectional in H-plane and bidirectional in E-plane. This antenna holds applications in many satellite communication transmissions, some Wi-Fi devices, cordless telephones, and weather radar systems. In this paper, an approach for multi-band antennas is proposed. First, a hexagonal patch is taken, it is fractured using Koch structure. The antenna shows compact dimensions with good S11 and pattern performance to be adopted for UWB applications.
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Gardill, M., G. Fischer, R. Weigel i A. Koelpin. "Single-element based ultra-wideband antenna array concepts for wireless high-precision 2-D local positioning". Advances in Radio Science 11 (4.07.2013): 297–305. http://dx.doi.org/10.5194/ars-11-297-2013.
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Abstract. We generally categorize the approaches for ultra-wideband antenna array design, and consequently propose simplified concepts for antenna arrays for a high-precision, ultra-wideband FMCW radar 2-D local positioning system to obtain robustness against multi path interference, perform angle of arrival analysis, as well as instantaneous heading estimation. We focus on low-cost and mechanical robust, industrial-application ready antennas. The antenna arrays are optimized for operation in the 5 GHz to 8 GHz frequency range and are designed towards supporting full omnidirectional 360° as well as partial half-plane direction of arrival estimation. Two different concepts for vehicle- as well as wall-mounted antenna array systems are proposed and discussed. We propose a wideband unidirectional bow-tie antenna array element having 97% impedance and 37% pattern bandwidth and a robust vehicle mounted omnidirectional antenna element having more than 85% impedance and pattern bandwidth.
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Taneja, Ashu, i Nitin Saluja. "A Comparison of Norm Based Antenna Selection and Random Antenna Selection with Regard to Energy Efficiency in Wireless System with Large Number of Users". International Journal of Sensors, Wireless Communications and Control 10, nr 2 (15.09.2020): 189–96. http://dx.doi.org/10.2174/2210327909666190319145555.
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Background: The paper considers the wireless system with large number of users (more than 50 users) and each user is assigned large number of antennas (around 200) at the Base Station (BS). Objective: The challenges associated with the defined system are increased power consumption and high complexity of associated circuitry. The antenna selection is introduced to combat these problems while the usage of linear precoding reduces computational complexity. The literature suggests number of antenna selection techniques based on statistical properties of signal. However, each antenna selection technique suits well to specific number of users. Methods: In this paper, the random antenna selection is compared with norm-based antenna selection. It is analysed that the random antenna selection leads to inefficient spectral efficiency if the number of users are more than 50 in Multi-User Multiple-Input Multiple Output (MU-MIMO) system. Results: The paper proposes the optimization of Energy-Efficiency (EE) with random transmit antenna selection for large number of users in MU-MIMO systems. Conclusion: Also the computation leads to optimization of number of transmit antennas at the BS for energy efficiency. The proposed algorithm results in improvement of the energy efficiency by 27% for more than 50 users.
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Abd, Reem Hikmat, i Hussein A. Abdulnabi. "Reconfigurable graphene-based multi-input multi-output antenna design for THz applications". Bulletin of Electrical Engineering and Informatics 12, nr 4 (1.08.2023): 2193–202. http://dx.doi.org/10.11591/beei.v12i4.4956.
Pełny tekst źródłaStreszczenie:
This paper presents a compact graphene-based multi-input multi-output (MIMO) antenna for wireless communications operating in frequency band (0.1-10) THz. This work has been performed with four ports microstrip antennas based on 37×88 μm² a silicon dioxide (Sio₂) substrate and copper on the ground layer, with high isolation by a series of unit cells of graphene selected between adjacent patches to reduce the transmission coefficient and antenna size. Graphene's chemical potential will change by changing the connected DC voltage, leading to bandwidth and resonant frequency variation. The simulation has a reflection coefficient is less than -10 dB at (4.5-10) THz of the frequency scale, mutual coupling (-15 dB), and the gain from (4.7-9) THz is (1.6-6.7254) dB. This paper aims to provide wideband, efficient and reconfigurable with simple graphene-based MIMO antenna for THz applications.
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Abd, Reem Hikmat, i Hussein A. Abdulnabi. "Reconfigurable graphene-based multi-input multi-output antenna design for THz applications". Bulletin of Electrical Engineering and Informatics 12, nr 4 (1.08.2023): 2193–202. http://dx.doi.org/10.11591/eei.v12i4.4956.
Pełny tekst źródłaStreszczenie:
This paper presents a compact graphene-based multi-input multi-output (MIMO) antenna for wireless communications operating in frequency band (0.1-10) THz. This work has been performed with four ports microstrip antennas based on 37×88 μm² a silicon dioxide (Sio₂) substrate and copper on the ground layer, with high isolation by a series of unit cells of graphene selected between adjacent patches to reduce the transmission coefficient and antenna size. Graphene's chemical potential will change by changing the connected DC voltage, leading to bandwidth and resonant frequency variation. The simulation has a reflection coefficient is less than -10 dB at (4.5-10) THz of the frequency scale, mutual coupling (-15 dB), and the gain from (4.7-9) THz is (1.6-6.7254) dB. This paper aims to provide wideband, efficient and reconfigurable with simple graphene-based MIMO antenna for THz applications.
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Shen, Aiguo, Guangsong Yang i Dezhi Wei. "Performance of multi-antenna wireless systems based on time reversal". Journal of Physics: Conference Series 2079, nr 1 (1.11.2021): 012025. http://dx.doi.org/10.1088/1742-6596/2079/1/012025.
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Abstract 5G wireless mobile communication system is faced with massive equipment access, information security and effective transmission is worth paying attention to. Wireless physical layer security mainly uses encryption principle to enhance the security of information transmission, while time reversal technology combines its electromagnetic characteristics and physical channel characteristics to improve the security performance of wireless communication system. In this paper, a signal transmission model of wireless multi-antenna communication system based on time reversal cavity is proposed and white Gaussian noise is introduced. The simulation results show that the space-time focusing characteristics of time reversal cavity can make the signal energy more concentrated on the target user, which can not only effectively alleviate the communication quality problems caused by multipath effect, but also ensure the security of information transmission process.
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He, Zhi Yong, i Jian Jun Zhang. "Study of Bridge Health Monitoring Scheme Based on GPS Multi-Antenna Technique". Advanced Materials Research 433-440 (styczeń 2012): 3400–3402. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.3400.
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Ongoing bridge collapse in both at home and abroad, makes people pay increasingly attention to bridge health monitoring. Bridge health monitoring which based on the GPS multiple antenna technology, GPRS wireless communications technology and so on, warning systems including GPS deformation monitoring subsystem, multiple antennas and safety assessment subsystem structure, can achieve bridge deformation data automatic acquisition, processing, analysis and structural safety evaluation and Internet remote transmission, automatic alarm function. Compared with the traditional method, the system has high accuracy and good data continuity, convenient operation, less investment etc, also has good social and economic benefits and broad application prospect.
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Dang, Khoa Le, Tung Thanh Vu, Tu Thanh Nguyen i Phuong Huu Nguyen. "Indoor optical wireless MIMO-OFDM system". Science and Technology Development Journal 17, nr 1 (31.03.2014): 5–16. http://dx.doi.org/10.32508/stdj.v17i1.1238.
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Indoor optical wireless systems have attracted attention, because they allow high-speed transmission without electromagnetic interference. Multi Input Multi Output (MIMO) techniques are very promising in providing high data rate or providing performance over fading channels. Orthogonal frequency division multiplexing (OFDM) can send multiple high speed signals by using orthogonal carrier frequencies. In this paper, we propose an optical wireless MIMO-OFDM system to achieve better performance. The signal of each optical transmit antenna is detected by using zero forcing (ZF) algorithm. We use the error vector magnitude (EVM) to predict BER performance. The analysis of bit error rate (BER) shows that the proposed system achieve better performance transmission than OMIMO system when transmitting the signal over reflection channels.
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Dilli, Ravilla. "Performance analysis of multi user massive MIMO hybrid beamforming systems at millimeter wave frequency bands". Wireless Networks 27, nr 3 (4.02.2021): 1925–39. http://dx.doi.org/10.1007/s11276-021-02546-w.
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AbstractMillimeter-wave (mmWave) and massive multi-input–multi-output (mMIMO) communications are the most key enabling technologies for next generation wireless networks to have large available spectrum and throughput. mMIMO is a promising technique for increasing the spectral efficiency of wireless networks, by deploying large antenna arrays at the base station (BS) and perform coherent transceiver processing. Implementation of mMIMO systems at mmWave frequencies resolve the issue of high path-loss by providing higher antenna gains. The motivation for this research work is that mmWave and mMIMO operations will be much more popular in 5G NR, considering the wide deployment of mMIMO in major frequency bands as per 3rd generation partnership project. In this paper, a downlink multi-user mMIMO (MU-mMIMO) hybrid beamforming communication system is designed with multiple independent data streams per user and accurate channel state information. It emphasizes the hybrid precoding at transmitter and combining at receiver of a mmWave MU-mMIMO hybrid beamforming system. Results of this research work give the tradeoff between multiple data streams per user and required number of BS antennas. It strongly recommends for higher number of parallel data streams per user in a mmWave MU-mMIMO systems to achieve higher order throughputs.
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Sun, Xiao Jin, i Zhi Wen Hu. "Research on Wireless Communication Technology Based on Cooperative Diversity". Applied Mechanics and Materials 416-417 (wrzesień 2013): 1561–64. http://dx.doi.org/10.4028/www.scientific.net/amm.416-417.1561.
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Cooperative diversity technique refers to that in the context of multi-users, several single antenna terminals create a virtual multi-antenna system to realize the dispatch and diversity of the periodic line by means of share each others antenna. The remarkable strong point of the cooperative diversity technique is that it can reduce the transmission power of the system, improve its handing capacity and effectively decrease its error rate. This paper is going to analyze the application of the cooperative diversity technique on the wireless communication technology and present the main problems of the cooperative diversify technique by introducing the related conceptions of the cooperative diversity technique.
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Wang, Xinhai, Liqiong Wu, Hua Chen, Wei Wang i Zhaoping Liu. "Frequency-Reconfigurable Microstrip Patch Antenna Based on Graphene Film". Electronics 12, nr 10 (19.05.2023): 2307. http://dx.doi.org/10.3390/electronics12102307.
Pełny tekst źródłaStreszczenie:
Fifth-generation mobile communication systems must connect to multiple wireless networks. In order to enable a single device to match the frequency bands of multiple wireless networks, it is usually necessary to use multiple single-band or multi-band antennas, which occupy a large amount of space inside a given device. Using frequency-reconfigurable antennas to replace multiple single-function antennas is an effective way to solve this problem. In this paper, we propose a frequency-reconfigurable microstrip patch antenna based on graphene film, which fills the slot of the radiating patch with graphene film. It was found that the surface current of the antenna can be changed by changing the conductivity of graphene through bias voltage, which allows the operating mode of the antenna to switch between a nearly slotted antenna and a nearly unslotted antenna to achieve frequency reconfigurability. By changing the bias voltage from 0 V to 9 V, the resonant frequency of the antenna can be switched from 29.6 GHz to 40 GHz, and the center frequency can by altered by 10.4 GHz, corresponding to the reflection coefficients of −26 dB and −20.8 dB, respectively. The antenna achieves good matching in both operating modes.
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Csathó, Botond Tamás, Bálint Péter Horváth i Péter Horváth. "Modeling the near-field of extremely large aperture arrays in massive MIMO systems". Infocommunications journal 12, nr 3 (2020): 39–46. http://dx.doi.org/10.36244/icj.2020.3.6.
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Massive multiple-input multiple-output (MIMO) is a key technology in modern cellular wireless communication systems to attain a very high system throughput in a dynamic multi-user environment. Massive MIMO relies on deploying base stations equipped with a large number of antenna elements. One possible way to deploy base stations equipped with hundreds or thousands of antennas is creating extremely large aperture arrays. In this paper, we investigate channel modeling aspects of massive MIMO systems with large aperture arrays, in which many users are located in the near-field of the aperture. Oneand two-dimensional antenna geometries, different propagation models, and antenna element patterns are compared in terms of inter-user correlation, condition number of the multi-user channel matrix, and spectral efficiency to identify key design parameters and essential modeling assumptions. As our analysis reveals by choosing spectral-efficiency as a design objective, the size of the aperture is the critical design parameter.
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She, Feng, Hsiao Hwa Chen i Hongyang Li. "Joint Angular and Time Diversity of Multi-Antenna CDMA Systems in Wireless Fading Channels". International Journal of Wireless Networks and Broadband Technologies 1, nr 1 (styczeń 2011): 1–14. http://dx.doi.org/10.4018/ijwnbt.2011010101.
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In this paper, a multi-antenna based receiver structure for direct sequence code division multiple access (DS/CDMA) system is proposed. The proposed scheme exploits the excellent time resolution of a CDMA RAKE receiver and uses an antenna array beamforming structure to resolve multipath returns in both angular and time domains. A much higher diversity gain than that based only on the time domain diversity can be achieved. This work suggests a new space-time diversity paradigm, namely angular-time diversity, which differs from traditional Alamouti-type space-time coded schemes. The impairments caused by multipath and multiuser interference are analyzed. The performance of the proposed receiver in multipath fading channel is explicitly evaluated. An expression for uncoded system bit error probability is derived. Simulation results show the performance improvement in terms of BER due to the use of multi-antenna in the receiver, and the results illustrate that the multi-antenna based receiver works effectively in resolving multipaths in both angular and time domains to achieve performance improvement due to angular and time diversity gain provided by the multi-antenna system.
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Chung, Ming-An, i Cheng-Wei Hsiao. "Dual-Band 6 × 6 MIMO Antenna System for Glasses Applications Compatible with Wi-Fi 6E and 7 Wireless Communication Standards". Electronics 11, nr 5 (4.03.2022): 806. http://dx.doi.org/10.3390/electronics11050806.
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Multi-user multiple-input and multiple-output (MU-MIMO) systems are the mainstream of current antenna design. This paper proposes a dual-band 6 × 6 MIMO glasses antenna for Wi-Fi 6E and Wi-Fi 7 indoor wireless communication. The six antennas have the same structure, all of which are F-shaped monopole antennas. They are on the left and right temples, at the upper and lower ends of the left and right frames, which effectively uses the space of the glasses. The substrate uses FR4 (εr=4.4, tanδ=0.02). The antenna design is compact (9 mm × 50 mm × 0.8 mm) and the glasses model is made of FR4. The overall model is similar to virtual reality (VR) glasses, which are convenient for a user to wear. The proposed antenna has three working frequency bands, at 2.4 GHz, 5 GHz, and 6 GHz. Through matching and optimization, the reflection coefficient can be lower than −10 dB. In addition, this paper evaluates two usage environments for simulation and measurement on the head and free space. The measurement results show that when the operating frequency band is at 2.45 GHz, the antenna efficiency is 86.1%, and the antenna gain is 1.9 dB. At 5.5 GHz, the antenna efficiency is 86.5%, and the antenna gain is 4.4 dB. At 6.7 GHz, the antenna efficiency is 85.4%, and the antenna gain is 3.7 dB. When the isolation of the MIMO antenna system is optimized, the low-frequency band is better than −10 dB, and the high-frequency band is better than −20 dB. The measured envelope correlation coefficient (ECC) values are all lower than 0.1.
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Zheng, Zi Wei. "Iterative Channel Estimation for the Chinese Digital Television Terrestrial Broadcasting Systems with the Multiple-Antenna Receivers". Advanced Engineering Forum 6-7 (wrzesień 2012): 439–44. http://dx.doi.org/10.4028/www.scientific.net/aef.6-7.439.
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Orthogonal frequency division multiplexing is an effective against multipath fading and high data throughput wireless channel transmission technology. Assistance with the inverse fast Fourier transform and fast Fourier transform operation, orthogonal frequency division multiplexing modulation and demodulation operations of the system convenient and convenient hardware implementation, orthogonal frequency division multiplexing, so in the modern digital television terrestrial broadcasting the system is widely used to support high performance bandwidth-efficient multimedia services. Broadband multi-carrier orthogonal frequency division multiplexing with multi-antenna and multi-antenna receiving system, to increase the diversity gain and improve the capacity of the system in different multipath fading channel. Accurate channel estimation in a simple channel equalization and decoding of broadband multi-carrier orthogonal frequency division multiple-antenna receiver and channel estimation accuracy and multiplexing system is very important, is the key to the performance of the overall broadband multi-carrier orthogonal frequency division multiplexing system in the multi-antenna receiver bit error rate. In this paper, iterative channel estimation to plan for digital terrestrial television broadcasting broadband multi-carrier orthogonal frequency division multiple antenna receiver multiplexing system proposal.
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Liu, Kechen, Dapeng Sun, Tao Su, Xu Zheng i Chaobo Li. "Design of Flexible Multi-Band Miniature Antenna Based on Minkowski Fractal Structure and Folding Technique for Miniature Wireless Transmission System". Electronics 12, nr 14 (12.07.2023): 3059. http://dx.doi.org/10.3390/electronics12143059.
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In light of the predicament concerning the small gain and narrow frequency range of miniature antennas, this paper employs the implementation of a fractal repeating array structure and a double-layer folding antenna structure. Through these measures, the miniature antenna is endowed with a high gain and an expansive frequency range, all within its diminutive size. The paper presents an exquisite and high-gain flexible multi-band antenna, utilizing a dielectric substrate composed of the flexible material polyimide, with a thickness of merely 0.1 mm. The implementation of this flexible material bestows a feathery mass of merely 4 mg upon the antenna, enabling it to seamlessly conform to various shapes. This makes it particularly well-suited for employment within miniature wireless transmission systems and compact mobile communication devices. In an endeavor to enhance impedance matching and radiation characteristics, the Minkowski fractal structure is ingeniously incorporated as the repeating array element. This repeating array structure assumes a pivotal role and, when combined with the double-layer folding antenna structure, achieves the objective of miniaturization. Remarkably, the antenna’s dimensions measure a mere 0.04 λ0 × 0.026 λ0 (λ0 @ 2.4 GHz). The proposed antenna boasts a remarkably diminutive volume of merely 5 × 3 × 0.1 mm3, with the measured and simulated results exhibiting a striking concurrence. Both sets of results demonstrate resonance across multiple frequencies, namely, 2.4 GHz, 5.2 GHz and 5.8 GHz. Furthermore, within the effective frequency range, the antenna attains a maximum gain of 1.65 dBi and 4.37 dBi, respectively.
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Xie, Feng, i Quan Wen Li. "Highway Slope Monitoring System Based Multi-Antenna GPS Network". Advanced Materials Research 261-263 (maj 2011): 1151–55. http://dx.doi.org/10.4028/www.scientific.net/amr.261-263.1151.
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Highway slope deformation monitoring is an important guarantee for the safety of road transport means, the conventional GPS monitoring system has many advantages, but the monitoring of high cost lead to difficult application. Through the use of GPS multi-antenna network technology, use of automatic control technology, low-noise signal amplification technology, the wireless GPRS data transmission technology, remote automated highway slope monitoring, GPS network monitoring system can greatly reduce the cost to obtain reliable slope deformation information.
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S. Muqdad, Zainab, Taha A. Elwi i Zaid A. Abdul Hassain. "A COMPACT MICROSTRIP ANTENNA BASED ON H-FRACTAL GEOMETRY FOR MULTI- BAND OPERATION". Journal of Engineering and Sustainable Development 25, Special (20.09.2021): 1–49. http://dx.doi.org/10.31272/jeasd.conf.2.1.7.
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This paper presents a compact, tri-bands, rectangular patch antenna based on H-Tree fractal slots structure for modern wireless communication systems has been introduced. The antenna structure consists of a 70.70×56mm2 rectangular patch printed on 173×173×1.6mm3 FR4 substrate. H-Tree slots fractal geometry with the defective ground plane on the other side to enhance gain and bandwidth. The suggested antenna is fed by a 50 Ω microstrip line. The antenna shows three resonance frequencies: 0.784, 1.158, and 1.772 GHz. The suggested antenna offers a total size reduction of about 75 %. The designed antenna possesses fractional bandwidths of 3.976 %, 7 %, and 2.7866 % for the first, second, and third resonances, respectively. Finally, the proposed antenna is a candidate for Global System for Mobile communications (GSM).
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Dey, Nilanjan, i Amira S. Ashour. "Antenna Design and Direction of Arrival Estimation in Meta-Heuristic Paradigm". International Journal of Service Science, Management, Engineering, and Technology 7, nr 3 (lipiec 2016): 1–18. http://dx.doi.org/10.4018/ijssmet.2016070101.
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Antennas are considered as a significant component in any wireless system. There are numerous factors and constraints that affect its design. Therefore, recently several algorithms are developed to allow the designers optimize the antenna with respect to numerous different criteria, general constraints and the desired performance characteristics. In recent years there has been an increasing attention to some novel evolutionary techniques, such as Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Ant Colony Optimization (ACO), Bacteria-Foraging (BF), Biogeography Based Optimization (BBO), and Differential Evolution (DE) that used for antenna optimization. The current study discussed three popular population-based meta-heuristic algorithms for optimal antenna design and direction of arrival estimation. Basically, single and multi-objective population-based meta-heuristic algorithms are included. Besides hybrid methods are highlighted. This paper reviews antenna array design optimization as well as direction of arrival optimization problem for different antennas configurations.
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Wang, Y., M. Reit i W. Mathis. "Entwurfskonzept einer Car2Car-Multiband-Dachantenne". Advances in Radio Science 10 (18.09.2012): 63–68. http://dx.doi.org/10.5194/ars-10-63-2012.
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Abstract. Due to the vastly increasing use of wireless services in the car, such as WiFi, Car2Car and LTE, the requirements on bandwidth and radiation pattern of the roof antenna systems become more challenging. In this work, a design concept for multi-band roof antenna systems is presented. We aim to get a higher bandwidth and an almost circular radiation pattern on the horizontal plane. Moreover, the antenna length is considered in order to fulfill the requirements set by construction ECE-regulations (ECE, 2010). The applicability of the design concept is not limited to multi-band roof antennas, it can also be used for a general wideband antenna design. For illustration of this concept, a multi-band roof antenna with a bandwidth of 780 MHz to 5.9 GHz and a near circular radiation pattern with an average gain of G = 3 dBi (at 5.9 GHz) on the horizontal plane is designed. The simulation and measurement results are presented.
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Christina, G. "A Review on Novel Microstrip Patch Antenna Designs and Feeding Techniques". IRO Journal on Sustainable Wireless Systems 4, nr 2 (25.07.2022): 110–20. http://dx.doi.org/10.36548/jsws.2022.2.005.
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Mobile technology is rapidly advancing nowadays due to its high impact in our day-to-day lives. As a result, there is an increasing need to study the advancement of antenna systems, which are regarded as fundamental equipment for wireless connectivity. Compared to the traditional large size antennas, microstrip patch antennas are now widely used in different applications such as smart phones, military, smart wearable devices etc. due to its unique characteristics such as lighter weight, reconfigurable structure, foldability, ease of fabrication, multi-frequency operations, and compactness. This research study presents a review on various microstrip patch antenna designs and the different antenna feed mechanisms available for 5G applications.
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Shuai, Haifeng, Rui Liu, Shibing Zhu, Changqing Li i Yi Fang. "Ergodic Capacity of NOMA-Based Multi-Antenna LMS Systems with Imperfect Limitations". Sensors 22, nr 1 (2.01.2022): 330. http://dx.doi.org/10.3390/s22010330.
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With the rapid development of land mobile satellite (LMS) systems, large scale sensors and devices are willing to request wireless services, which is a challenge to the quality of service requirement and spectrum resources utilization on onboard LMS systems. Under this situation, the non-orthogonal multiple access (NOMA) is regarded as a promising technology for improving spectrum efficiency of LMS systems. In this paper, we analyze the ergodic capacity (EC) of NOMA-based multi-antenna LMS systems in the presence of imperfect limitations, i.e., channel estimation errors, imperfect successive interference cancellation, and co-channel interference. By considering multiple antennas at the satellite and terrestrial sensor users, the closed-form expression for EC of the NOMA-based LMS systems with imperfect limitations is obtained. Monte Carlo simulations are provided to verify theoretical results and reveal the influence of key parameters on system performance.
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Fuschini, Franco, Marina Barbiroli, Giovanna Calò, Velio Tralli, Gaetano Bellanca, Marco Zoli, Jinous Shafiei Dehkordi, Jacopo Nanni, Badrul Alam i Vincenzo Petruzzelli. "Multi-Level Analysis of On-Chip Optical Wireless Links". Applied Sciences 10, nr 1 (25.12.2019): 196. http://dx.doi.org/10.3390/app10010196.
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Networks-on-chip are being regarded as a promising solution to meet the on-going requirement for higher and higher computation capacity. In view of future kilo-cores architectures, electrical wired connections are likely to become inefficient and alternative technologies are being widely investigated. Wireless communications on chip may be therefore leveraged to overcome the bottleneck of physical interconnections. This work deals with wireless networks-on-chip at optical frequencies, which can simplify the network layout and reduce the communication latency, easing the antenna on-chip integration process at the same time. On the other end, optical wireless communication on-chip can be limited by the heavy propagation losses and the possible cross-link interference. Assessment of the optical wireless network in terms of bit error probability and maximum communication range is here investigated through a multi-level approach. Manifold aspects, concurring to the final system performance, are simultaneously taken into account, like the antenna radiation properties, the data-rate of the core-to core communication, the geometrical and electromagnetic layout of the chip and the noise and interference level. Simulations results suggest that communication up to some hundreds of μm can be pursued provided that the antenna design and/or the target data-rate are carefully tailored to the actual layout of the chip.
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Vincy Lumina, A., i M. Sangeetha. "Multiband Monopole Antenna Design for 2G-5G Applications". Journal of Physics: Conference Series 2335, nr 1 (1.09.2022): 012010. http://dx.doi.org/10.1088/1742-6596/2335/1/012010.
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Abstract Multi frequency antennas are in high demand as the wireless communication system is developing rapidly. To access internet in a mobile device, 2G-5G and WLAN are used that covers 1.8 GHz – 6 GHz. This paper proposes a design of low profile multiband monopole antenna for all 2G-5G communications, WLAN and for WiMAX application. The antenna design has a diamond shaped radiator, a cylinder to achieve better resonance, and a defective ground. The proposed antenna has a compact size of 30 mm x 44.5 mm. This antenna covers 2G (1.8 GHz), 3G (2.1 GHz), 4G (2.4 GHz), 5G (3.5 GHz), WLAN (2.4/3.6/5 GHz) and WiMAX (2.3/3.5/5.8 GHz) and is shown from the measured results. From these results it is shown that the produced antenna produces six distinct bands with good the simulation outcomes.
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Jit Singh, Mandeep Singh, Wan Syahrum Wan Saleh, Amer T. Abed i Muhammad Ashraf Fauzi. "A Review on Massive MIMO Antennas for 5G Communication Systems on Challenges and Limitations". Jurnal Kejuruteraan 35, nr 1 (30.01.2023): 95–103. http://dx.doi.org/10.17576/jkukm-2023-35(1)-09.
Pełny tekst źródłaStreszczenie:
High data rate transfers, high-definition streaming, high-speed internet, and the expanding of the infrastructure such as the ultra-broadband communication systems in wireless communication have become a demand to be considered in improving quality of service and increase the capacity supporting gigabytes bitrate. Massive Multiple-Input Multiple-Output (MIMO) systems technology is evolving from MIMO systems and becoming a high demand for fifth-generation (5G) communication systems and keep expanding further. In the near future, massive MIMO systems could be the main wireless systems of communications technology and can be considered as a key technology to the system in daily lives. The arrangement of the huge number of antenna elements at the base station (BS) for uplink and downlink to support the MIMO systems in increasing its capacity is called a Massive MIMO system, which refers to the vast provisioning of antenna elements at base stations over the number of the single antenna of user equipment. Massive MIMO depends on spatial multiplexing and diversity gain in serving users with simple processing signal of uplink and downlink at the BS. There are challenges in massive MIMO system even though it contains numerous number of antennas, such as channel estimation need to be accurate, precoding at the BS, and signal detection which is related to the first two items. On the other hand, in supporting wideband cellular communication systems and enabling low latency communications and multi-gigabit data rates, the Millimeter-wave (mmWave) technology has been utilized. Also, it is widely influenced the potential of the fifth-generation (5G) New Radio (NR) standard. This study was specifically review and compare on a few designs and methodologies on massive MIMO antenna communication systems. There are three limitations of those antennas were identified to be used for future improvement and to be proposed in designing the massive MIMO antenna systems. A few suggestions to improve the weaknesses and to overcome the challenges have been proposed for future considerations.
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Alieksieiev, V. O., D. V. Gretskih, D. S. Gavva i V. G. Lykhograi. "Wireless power transmission technologies". Radiotekhnika, nr 211 (30.12.2022): 114–32. http://dx.doi.org/10.30837/rt.2022.4.211.09.
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The article consists of three parts. The analysis of existing technologies of wireless power transfer (WPT) is carried out in the first part. It is noted that one of the factors that determines the choice of one or another WPT technology is the distance over which the power is transmitted and the type of electromagnetic (EM) energy used. The essence of WPT technologies in the near zone, Fresnel zone and Fraunhofer zone is explained. A generalized block diagram of the WPT system is presented. Areas of application and trends in the further development of the WPT technologies over short distances using induction and resonance methods, the WPT technologies over long distances, the technology of EM energy harvesting from the surrounding space and its conversion into direct current for powering low-power devices are considered.
The achievements of the team of the antenna laboratory of the Kharkiv National University of Radio Electronics (KhNURE) in the area of WPT are presented in the second part of the article. Namely, the electrodynamics’ approach is considered which is based on a single idea about the functioning of WPT systems and which include antennas and their circuits and ways of excitation with nonlinear elements. The stages of building a nonlinear mathematical model (MM) of the electrodynamics’ level of the WPT system are presented, according to which the entire WPT system, which generally includes the transmitting subsystem and the receiving subsystem, is considered as a single multi-input antenna system with nonlinear characteristics. The proposed MM provides a complete representation of the WPT systems operation of a wide class and purpose, in which fundamentally different WPT technologies are used.
The third part of the article presents new results related to continued research. The analysis of the adequacy of the developed MM of WPT system is carried out. The results of simulation of WPT systems with the induction method of energy transfer (near zone) and their comparison with theoretical and experimental data of other authors showed the reliability and universality of the proposed approach and the MM of WPT system developed on its basis.
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Jordão, Marina, Diogo Pires, Daniel Belo, Pedro Pinho i Nuno Borges Carvalho. "3D Antenna Characterization for WPT Applications". Sensors 21, nr 13 (29.06.2021): 4461. http://dx.doi.org/10.3390/s21134461.
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The main goal of this paper is to present a three-dimensional (3D) antenna array to improve the performance of wireless power transmission (WPT) systems, as well as its characterization with over-the-air (OTA) multi-sine techniques. The 3D antenna consists of 15 antenna elements attached to an alternative 3D structure, allowing energy to be transmitted to all azimuth directions at different elevation angles without moving. The OTA multi-sine characterization technique was first utilized to identify issues in antenna arrays. However, in this work, the technique is used to identify which elements of the 3D antenna should operate to transmit the energy in a specific direction. Besides, the 3D antenna design description and its characterization are performed to authenticate its operation. Since 3D antennas are an advantage in WPT applications, the antenna is evaluated in a real WPT scenario to power an RF–DC converter, and experimental results are presented.
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Hu, Feng, Li Biao Jin i Jian Zeng Li. "A Parallel Space-Time Block Code Based Transmission Scheme". Advanced Materials Research 605-607 (grudzień 2012): 1959–64. http://dx.doi.org/10.4028/www.scientific.net/amr.605-607.1959.
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We present a new transmit strategy based on modified Alamouti codes for the simple two branch transmit diversity scheme. The OFDM payload cells from the output of the frequency interleaver is done on one transmit antenna, and the encoding is proceeded on another branch. The proposed encoding scheme can significantly simplify the processes of transforming SISO into MIMO in wireless communication systems. The scheme may easily be generalized to two transmit antennas and M receive antennas to provide a diversity order of 2M, its coding gain is similar to Alamouti code. Computer simulations are performed to investigate the performance of the proposed parallel STBC scheme in a multi-input (MI) system.
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Isaac Kuma Yeboah, Richard Brace, Kwabena Agyapong-Kondua, Matthew Asiedu i Henrritta Kuma Yeboah. "Fabrication and optimization of bi-quad antenna and energy-efficient balanced RF power amplifier for 5G-LTE multi-carrier applications". ITU Journal on Future and Evolving Technologies 3, nr 3 (15.12.2022): 874–85. http://dx.doi.org/10.52953/wcqw1171.
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Wireless technology is presently one of the most actively researched fields of digital communication systems. Wireless communication technologies are insufficient without an understanding of antenna design and operation. A wide range of radio frequency equipment, including microwave antennas, microwave ovens, cordless telephones, and medical devices, utilize the 2.4 GHz band. In this article, a parabolic mesh dish was used to build and improve a bi-quad antenna with a central working frequency of 2.445 GHz. The bi-quad antenna was put in a parabolic mesh dish to optimize wave propagation. The findings show that the antenna obtained a signal strength range of 70% to 80%, increasing the directivity of WLAN coverage. The bi-quad antenna feed was placed in the center of a mesh dish, which assists in focusing radio waves onto the antenna. The bi-quad antenna outperformed the omnidirectional antenna, which had a signal strength of 56%. The results of each antenna test were separately simulated in MATLAB. The combined impact of bi-quad and parabolic was then duplicated using mathematical models, resulting in a unique waveform propagation pattern known as para-quad, which improved performance. A balanced RF power amplifier was conceived and built in this study. A 2.620 - 2.690GHz frequency range on a large signal Si-LDMOS transistor model achieves 53% PAE, 41dBm power output, and 14 dB gain at the P1dB saturation point.