Journal articles: 'Active antenna'

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Sabban, Albert. "Active Compact Wearable Body Area Networks for Wireless Communication, Medical and IoT Applications." Applied System Innovation 1, no. 4 (November 23, 2018): 46. http://dx.doi.org/10.3390/asi1040046.

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The development of compact wearable antennas and transceivers for communication, IoT (Internet of Things), and biomedical systems will be presented in this paper. Development of Compact efficient wearable antennas is one of the major challenges in development of wearable communication, IoT, and medical systems. The main goal of wireless body area networks (BANs), WBANs, is to provide continuously medical data to the physician. Body area network (BAN) antennas should be flexible, lightweight, compact, and have low production cost. However, low efficiency is the major disadvantage of small printed antennas. Microstrip antennas resonant frequency is altered, due to environment conditions, different antenna locations, and different system operation modes. These disadvantages may be solved by using compact active and tunable antennas. A new class of wideband active wearable antennas for medical applications is presented in this paper. Amplifiers may be connected to the wearable antenna feed line to increase the system dynamic range. Small lightweight batteries supply the bias voltage to the active components. An active dual polarized antenna is presented in this paper. The active dual polarized antenna gain is 14 ± 3 dB for frequencies ranging from 380 to 600 MHz. The active transmitting dual polarized antenna output power is around 18 dBm. A voltage-controlled diode, varactor, may be used to control the antenna electrical performance at different environments. For example, an antenna located in patient stomach area has VSWR (Voltage Standing Wave Ratio) better than 2:1 at 434 MHz. However, if the antenna will be placed on the patient back, it may resonate at 420 MHz. By varying the varactor bias voltage, the antenna resonant frequency may be shifted from 420 to 434 MHz. An ultra-wideband passive and active printed slot antenna may be employed in wideband wearable communication systems. The active slot antenna gain is 13 ± 2 dB for frequencies from 800 MHz to 3 GHz.

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Kumari, Bibha, and Nisha Gupta. "Multifrequency Oscillator-Type Active Printed Antenna Using Chaotic Colpitts Oscillator." International Journal of Microwave Science and Technology 2014 (November 30, 2014): 1–10. http://dx.doi.org/10.1155/2014/675891.

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This paper presents a new concept to realize a multifrequency Oscillator-type active printed monopole antenna. The concept of period doubling route to chaos is exploited to generate the multiple frequencies. The chaotic Colpitts oscillator is integrated with the printed monopole antenna (PMA) on the same side of the substrate to realize an Oscillator-type active antenna where the PMA acts as a load and radiator to the chaotic oscillator. By changing the bias voltage of the oscillator, the antenna can be made to operate at single or multiple frequencies. To test the characteristics of the antenna at single and multiple frequencies of operation, two similar prototype models of printed monopole broadband antennas are developed. One of these antennas used at transmit side is fed by the chaotic Colpitts oscillator while the other is used as the receive antenna. It is observed that the antenna receives single or multiple frequencies simultaneously for particular values of the bias voltage of the oscillator at the transmit end.

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Ali, Khamis, Norun Abdul Malek, Ahmad Zamani Jusoh, Sarah Yasmin Mohamad, Zuhairiah Zainal Abidin, and Ani Liza Asnawi. "Design and optimize microstrip patch antenna array using the active element pattern technique." Bulletin of Electrical Engineering and Informatics 8, no. 3 (September 1, 2019): 994–1003. http://dx.doi.org/10.11591/eei.v8i3.1516.

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Microstrip patch antennas are widely used in modern day communication devices due to their light weight, low cost and ease of fabrication. In this paper, we have designed and fabricated two Microstrip Patch Antennas (slotted-ring and truncated-slotted ring) and array at 2.4 GHz for Wireless Local Area Network (WLAN) applications using Computer Simulation Technology, CST. The antenna design consists of rectangular radiating patch on Rogers RT5880 substrate and is excited by using coaxial probe feeding technique. The truncated-slotted ring has been designed on top of the radiating patch to improve bandwidth. The simulation and measurement results of the both antennas are in close agreement with each other. Due to the good agreement of simulation and measurement results of truncated-slotted ring antenna in comparison with slotted-ring antenna, it has been selected for antenna array design. The simulated and measured S11 of truncated-slotted ring antenna shows -21dB and -15.6 dB at 2.4 GHz respectively. Then, the antenna has been formed into 1x4 array in order to observe its beamforming capability. The proposed antenna array is suitable for 802.11b/g/n Wi-Fi standard which is proposed to be used for IoT.

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Capece, P. "Active SAR Antennas: Design, Development, and Current Programs." International Journal of Antennas and Propagation 2009 (2009): 1–11. http://dx.doi.org/10.1155/2009/796064.

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The paper presents the design guidelines for Active SAR Antennas followed for the development of COSMO Sky Med SAR Antenna Subsystem. They have brought to define the antenna architecture, the RF, and electrical requirements for all the antenna RF, digital and power units, taking into account the available technologies and achievable performance. The antenna design is described for what the main subsystems is concerned, such as RF, power, digital, including mechanical and thermal aspects. Finally the paper reports also a brief description of the most recent development carried out in Canada and in Europe in the last ten years, including the on-going programs.

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Ojaroudi Parchin, Naser, Haleh Jahanbakhsh Basherlou, Yasir Al-Yasir, Raed Abd-Alhameed, Ahmed Abdulkhaleq, and James Noras. "Recent Developments of Reconfigurable Antennas for Current and Future Wireless Communication Systems." Electronics 8, no. 2 (January 26, 2019): 128. http://dx.doi.org/10.3390/electronics8020128.

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Reconfigurable antennas play important roles in smart and adaptive systems and are the subject of many research studies. They offer several advantages such as multifunctional capabilities, minimized volume requirements, low front-end processing efforts with no need for a filtering element, good isolation, and sufficient out-of-band rejection; these make them well suited for use in wireless applications such as fourth generation (4G) and fifth generation (5G) mobile terminals. With the use of active materials such as microelectromechanical systems (MEMS), varactor or p-i-n (PIN) diodes, an antenna’s characteristics can be changed through altering the current flow on the antenna structure. If an antenna is to be reconfigurable into many different states, it needs to have an adequate number of active elements. However, a large number of high-quality active elements increases cost, and necessitates complex biasing networks and control circuitry. We review some recently proposed reconfigurable antenna designs suitable for use in wireless communications such as cognitive-ratio (CR), multiple-input multiple-output (MIMO), ultra-wideband (UWB), and 4G/5G mobile terminals. Several examples of antennas with different reconfigurability functions are analyzed and their performances are compared. Characteristics and fundamental properties of reconfigurable antennas with single and multiple reconfigurability modes are investigated.

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Wang, Congsi, Haihua Li, Kang Ying, Qian Xu, Na Wang, Baoyan Duan, Wei Gao, Lan Xiao, and Yuhu Duan. "Active Surface Compensation for Large Radio Telescope Antennas." International Journal of Antennas and Propagation 2018 (2018): 1–17. http://dx.doi.org/10.1155/2018/3903412.

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With the development of radio telescope antennas with large apertures, high gain, and wide frequency bands, compensation methods, such as mechanical or electronic compensation, are obviously essential to ensure the electrical performance of antennas that work in complex environments. Since traditional compensation methods can only adjust antenna pointing but not the surface accuracy, which are limited for obtaining high surface precision and aperture efficiency, active surface adjustment has become an indispensable tool in this field. Therefore, the development process of electrical performance compensation methods for radio telescope antennas is introduced. Further, a series of analyses of the five key technologies of active surface adjustment is presented. Then, four typical large antennas that have been designed with active main reflector technology are presented and compared. Finally, future research directions and suggestions for reflector antenna compensation methods based on active surface adjustment are presented.

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Parshina, E. S., and K. Yu Cheredeev. "USE OF AN ACTIVE PHASED ARRAY ANTENNA IN RADAR’S SIDE LOBES CANCELLATION SYSTEM." Issues of radio electronics, no. 1 (January 20, 2019): 19–23. http://dx.doi.org/10.21778/2218-5453-2019-1-19-23.

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The paper describes an example of designing the radar’s side lobes cancellation system. It is based on the scheme of one channel interference canceler. The analysis of the antennas, which are ussually used in radar’s side lobes cancellation systems, is done, and active phased array antenna is chosen as an antenna of the radar’s side lobes cancellation system. The array pattern was formed by using antenna synthesis iterative method in order to fulfill the radar’s side lobes cancellation system’s antenna requirements. The antenna modeling results and its’ analysis are presented. The radar’s side lobes cancellation system with active phased array antenna eliminates intentional noise or impulse interference from any side lobe directions of the radar antenna.

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Constantinides, Antonios, and Haris Haralambous. "A Compact Wideband Active Two-Dipole HF Phased Array." Applied Sciences 11, no. 19 (September 26, 2021): 8952. http://dx.doi.org/10.3390/app11198952.

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The design and construction of an upgraded HF quarter-wavelength two-dipole active array with 90° difference feed was implemented in the course of a research project to perform a directional (azimuthal) investigation of interference at HF. The lack of affordable compact antennas to meet the project requirements was the incentive to develop a compact unidirectional antenna, with the maximum possible front-to-back ratio at frequencies of 20–30 MHz, where the dimensions of traditional passive antennas are enormous. By installing a low-noise very-high-input impedance amplifier in each dipole of the array, the effect of the mutual coupling between the two dipoles was reduced, improving the front-to-back (F/B) ratio over a wide frequency range. Electronic steering, easy polarization adjustment, and fast and easy deployment were the key requirements for the construction of the antenna. Therefore, a light and compact design was of the utmost importance to meet the space limitations at the monitoring site, which did not allow the deployment of a traditional HF directional antenna that employs a very long boom and elements.

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Tzanidis, Ioannis, Yang Li, Gary Xu, Ji-Yun Seol, and JianZhong (Charlie) Zhang. "2D Active Antenna Array Design for FD-MIMO System and Antenna Virtualization Techniques." International Journal of Antennas and Propagation 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/873530.

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Full dimension MIMO (FD-MIMO) is one of the key technologies presently studied in the 3GPP for the next generation long-term evolution advanced (LTE-A) systems. By incorporating FD-MIMO into LTE/LTE-A systems, it is expected that system throughput will be drastically improved beyond what is possible in conventional LTE systems. This paper presets details on the 2D active antenna array design for FD-MIMO systems supporting 32 antenna elements. The FD-MIMO system allows for dynamic and adaptive precoding to be performed jointly across all antennas thus achieving more directional transmissions in the azimuth and elevation domains simultaneously, to a larger number of users. Finally, we discuss 2D antenna array port virtualization techniques for creating beams with wide coverage, necessary for broadcasting signals to all users within a sector, such as the CRS (Common Reference Signal).

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Saltin, B. D., Y. Matsumura, A. Reid, J. F. Windmill, S. N. Gorb, and J. C. Jackson. "Material stiffness variation in mosquito antennae." Journal of The Royal Society Interface 16, no. 154 (May 2019): 20190049. http://dx.doi.org/10.1098/rsif.2019.0049.

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The antennae of mosquitoes are model systems for acoustic sensation, in that they obey general principles for sound detection, using both active feedback mechanisms and passive structural adaptations. However, the biomechanical aspect of the antennal structure is much less understood than the mechano-electrical transduction. Using confocal laser scanning microscopy, we measured the fluorescent properties of the antennae of two species of mosquito— Toxorhynchites brevipalpis and Anopheles arabiensis —and, noting that fluorescence is correlated with material stiffness, we found that the structure of the antenna is not a simple beam of homogeneous material, but is in fact a rather more complex structure with spatially distributed discrete changes in material properties. These present as bands or rings of different material in each subunit of the antenna, which repeat along its length. While these structures may simply be required for structural robustness of the antennae, we found that in FEM simulation, these banded structures can strongly affect the resonant frequencies of cantilever-beam systems, and therefore taken together our results suggest that modulating the material properties along the length of the antenna could constitute an additional mechanism for resonant tuning in these species.

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Stengl, M., and R. Zintl. "NADPH diaphorase activity in the antennae of the hawkmoth Manduca sexta." Journal of Experimental Biology 199, no. 5 (May 1, 1996): 1063–72. http://dx.doi.org/10.1242/jeb.199.5.1063.

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Biochemical and physiological studies suggested that increases in the levels of cyclic GMP in insect antennal receptor cells play a role in olfactory adaptation. As inositol-trisphosphate-dependent Ca2+ influx appears to precede the increase in intracellular cyclic GMP levels, it was hypothesized that a Ca2+-dependent mechanism might stimulate the guanylyl cyclase. The present study used histochemical staining for NADPH diaphorase to examine whether antennal receptor neurones of male Manduca sexta could contain nitric oxide synthase. This Ca2+/calmodulin-dependent enzyme is a prerequisite for nitric-oxide-dependent stimulation of guanylyl cyclase and possesses NADPH diaphorase activity. It was found that a subpopulation of olfactory receptor neurones as well as mechano-, thermo- and hygroreceptors on the moth antenna are NADPH-diaphorase-positive. Staining was also seen in non-neuronal cells. In the developing antenna, the NADPH-diaphorase-dependent staining was first observed at pupal stage 13-14, at approximately the same time as the antennal receptor neurones became physiologically active. The number and location of stained receptor cells was highly variable, and significantly more pheromone-sensitive sensilla were NADPH-diaphorase-positive in pheromone-stimulated antennae. This suggests that the enzyme is transiently activated by pheromone rather than being continuously active.

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Dierck, Arnaut, Sam Agneessens, Frederick Declercq, Bart Spinnewyn, Gert-Jan Stockman, Patrick Van Torre, Luigi Vallozzi, et al. "Active textile antennas in professional garments for sensing, localisation and communication." International Journal of Microwave and Wireless Technologies 6, no. 3-4 (March 12, 2014): 331–41. http://dx.doi.org/10.1017/s175907871400018x.

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New wireless wearable monitoring systems integrated in professional garments require a high degree of reliability and autonomy. Active textile antenna systems may serve as platforms for body-centric sensing, localisation, and wireless communication systems, in the meanwhile being comfortable and invisible to the wearer. We present a new dedicated comprehensive design paradigm and combine this with adapted signal-processing techniques that greatly enhance the robustness and the autonomy of these systems. On the one hand, the large amount of real estate available in professional rescue worker garments may be exploited to deploy multiple textile antennas. On the other hand, the size of each radiator may be designed large enough to ensure high radiation efficiency when deployed on the body. This antenna area is then reused by placing active electronics directly underneath and energy harvesters directly on top of the antenna patch. We illustrate this design paradigm by means of recent textile antenna prototypes integrated in professional garments, providing sensing, positioning, and communication capabilities. In particular, a novel wearable active Galileo E1-band antenna is presented and fully characterized, including noise figure, and linearity performance.

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Murtala, Sheriff, Tasnim Holoubi, Nishal Muchena, Manar Mohaisen, and Kang-Sun Choi. "On the Performance of the Multiple Active Antenna Spatial Modulation with 3-Dimensional Constellation." Applied Sciences 10, no. 11 (May 27, 2020): 3718. http://dx.doi.org/10.3390/app10113718.

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In spatial modulation (SM), a single signal symbol is transmitted from a given physical antenna, where both the signal symbol and the antenna index carry information. SM with multiple active antennas (MA-SM) transmits several signal symbols from a combination of antennas at each channel use, thereby increasing the spectral efficiency. MA-SM is proposed in combination with a new 3-dimensional constellation, where signal symbols transmitted from a given antenna combination are rotated before transmission. In this paper, we derived an upper-bound on the error probability of the MA-SM as a function of the rotation angles. The search for the optimal rotation angles is modeled as a multi-objective optimization problem. We concluded based on both analytical and simulation results that the 3-dimensional constellation with the optimal angles achieved negligible improvement. Therefore, we do not recommend using the 3-dimensional constellation with the MA-SM system.

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KANAYAMA, Naoki, Makoto KANEKO, and Toshio TSUJI. "3D Artificial Active Antenna." Transactions of the Society of Instrument and Control Engineers 31, no. 12 (1995): 1915–23. http://dx.doi.org/10.9746/sicetr1965.31.1915.

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Humphrey, D. E. J., V. F. Fusco, and S. Drew. "Active antenna array behavior." IEEE Transactions on Microwave Theory and Techniques 43, no. 8 (1995): 1819–25. http://dx.doi.org/10.1109/22.402266.

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Drew, S., and V. F. Fusco. "Phase modulated active antenna." Electronics Letters 29, no. 10 (May 13, 1993): 835–36. http://dx.doi.org/10.1049/el:19930558.

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Kumar, Somesh, and Ms Monika. "Study of Effect of Variations in slot dimensions on Fractal Patch antenna Performance." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 5, no. 1 (June 23, 2013): 41–48. http://dx.doi.org/10.24297/ijct.v5i1.4385.

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An antenna is a device that is made to efficiently radiate and receive radiated Electromagnetic waves. Microstrip antennas are attractive due to their light weight, conformability and low cost. These antennas can be integrated with printed strip-line feed networks and active devices. This is a relatively new area of antenna engineering. For reducing the size of antenna, fractal geometries have been introduced in the design of patch antenna. Fractal antennas also called as space filling curves are very compact, multiband or wideband, and have useful applications in cellular telephone and microwave communications. In our research work, we have used IE3D software for designing the antenna. We study the effect of variations of slot dimensions on antenna performance so as to obtain good results. In this research work, four different fractal patch antennas are designed. The rectangular base geometry is same for the all four antennas but the elliptical slot dimensions differ. In simulation, S parameters of all four antennas are analyzed. From the S parameter displays, comparison of all four antennas is done on the basis of three parameters that are: Lowest frequency, Multiband and S11 values. The simulation results shows that as the elliptical slot dimension decreases on rectangular patch antenna, the performance of fractal patch antenna improves on the basis of three factors that are lowest frequency, multiband and s11 values.

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Sabban, Albert. "New Compact Wearable Metamaterials Circular Patch Antennas for IoT, Medical and 5G Applications." Applied System Innovation 3, no. 4 (October 8, 2020): 42. http://dx.doi.org/10.3390/asi3040042.

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The development of compact passive and active wearable circular patch metamaterials antennas for communication, Internet of Things (IoT) and biomedical systems is presented in this paper. Development of compact efficient low-cost wearable antennas are one of the most significant challenges in development of wearable communication, IoT and medical systems. Moreover, the advantage of an integrated compact low-cost feed network is attained by integrating the antenna feed network with the antennas on the same printed board. The efficiency of communication systems may be increased by using efficient passive and active antennas. The system dynamic range may be improved by connecting amplifiers to the printed antenna feed line. Design, design considerations, computed and measured results of wearable circular patch meta-materials antennas with high efficiency for 5G, IoT and biomedical applications are presented in this paper. The circular patch antennas electrical parameters on the human body were analyzed by using commercial full-wave software. The circular patch metamaterial wearable antennas are compact and flexible. The directivity and gain of the antennas with Circular Split-Ring Resonators (CSRR) is higher by 2.5dB to 3dB than the antennas without CSRR. The resonant frequency of the antennas without CSRR is higher by 6% to 9% than the antennas with CSRR. The computed and measured bandwidth of the stacked circular patch wearable antenna with CSRR for IoT and medical applications is around 12%, for S11 lover than −6dB. The gain of the circular patch wearable antenna with CSRR is around 8dBi.

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Wang, Lu, Zhihai Wang, Congsi Wang, Guozhou Li, and Lei Yin. "Multiobjective Optimization Method for Multichannel Microwave Components of Active Phased Array Antenna." Mathematical Problems in Engineering 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/5398308.

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Multichannel microwave components are widely used and the active phased array antenna is a typical representative. The high power generated from T/R modules in active phased array antenna (APAA) leads to the degradation of its electrical performances, which seriously restricts the development of high-performance APAA. Therefore, to meet the demand of thermal design for APAA, a multiobjective optimization design model of cold plate is proposed. Furthermore, in order to achieve temperature uniformity and case temperature restrictions of APAA simultaneously, optimization model of channel structure is developed. Besides, an airborne active phased array antenna was tested as an example to verify the validity of the optimization model. The valuable results provide important reference for engineers to enhance thermal design technology of antennas.

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Bubnov, I. N., O. O. Konovalenko, P. L. Tokarsky, O. M. Korolev, S. M. Yerin, and L. O. Stanislavsky. "CREATION AND APPROBATION OF A LOW-FREQUENCY RADIO ASTRONOMY ANTENNA FOR STUDIES OF OBJECTS OF THE UNIVERSE FROM THE MOON'S FARSIDE." Radio physics and radio astronomy 26, no. 3 (September 14, 2021): 197–210. http://dx.doi.org/10.15407/rpra26.03.197.

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Purpose: Theoretical and experimental studies of the active antenna – an element of the low-frequency radio telescope antenna array for the future observatory on the farside of the Moon. Design/methodology/approach: To study the active antenna, consisting of a complex-shaped dipole and a low-noise amplifier, we used its mathematical model in the form of a two-port network, whose electrical parameters are set by the scattering matrix, the noise parameters being set by the covariance matrix of the spectral densities of noise waves. This model allows ma[1]king the correct analysis of the signal-to-noise ratio at the active antenna output with account for the external and internal noise sources. The modelling results were compared with those of experimental measurements of antenna characteristics. A series of radio astronomy observations were made with the developed antenna under the Earth environmental conditions. Findings: A numerical analysis of the radio telescope active antenna parameters has been made in a wide frequency range of 4–40 MHz. Two versions of the low-noise amplifier were developed to operate in the active antenna under the space and Earth environmental conditions. Under the Earth conditions, it has been experimentally proven that the range of problems, which such radio telescopes can effectively solve at low frequencies, is quite wide – from the solar research to the search for cosmological effects. Conclusions: The results of numerical simulations and experimental measurements obtained in this work have shown a satisfactory agreement between them for the most of the frequency range. The results of this work can be useful in the research and development of active antennas designed for operation at the decameter and hectometer wavelength ranges, particularly those intended for using under the space environmental conditions. Keywords: active antenna, Moon, radio astronomy observations, sensitivity

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Ding, Tongyu, Shaoqing Zhang, Liang Zhang, and Yanhui Liu. "Smart Cylindrical Dome Antenna Based on Active Frequency Selective Surface." International Journal of Antennas and Propagation 2017 (2017): 1–14. http://dx.doi.org/10.1155/2017/5901625.

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In this paper, we proposed a beamforming antenna, which is realized using an omnidirectional antenna in the center surrounded by a cylindrical smart dome. The smart dome is made of 16 active frequency selective surface columns of which the amplitude and phase response can be continuously tuned by varying the bias voltages of the employed varactors. Thus, the performance of the proposed antenna could achieve higher gain, better nulling level, and more agility than many switch methods-based cylindrical reconfigurable antennas. Moreover, in order to overcome the unavailable analytical synthesis caused by complex mutual coupling between columns, we develop a genetic algorithm based optimization system and conducted a serial of experiments to evaluate the high-gain, nulling, continuously steering, and frequency-invariant ability. The results show that, during the frequency tunable range of the AFSS (2.0 GHz to 2.7 GHz), the antenna can offer an additional gain of up to 6.57 dB and nulling level of −56.41 dBi. For the high-gain modes, the −3 dB beam widths are 26°–34°, which offers enhanced angular resolution compared with other reported beam-sweeping work. Furthermore, the radiation pattern is continuously steerable.

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Thevenot, M., C. Menudier, A. El Sayed Ahmad, G. Zakka El Nashef, F. Fezai, Y. Abdallah, E. Arnaud, F. Torres, and T. Monediere. "Synthesis of Antenna Arrays and Parasitic Antenna Arrays with Mutual Couplings." International Journal of Antennas and Propagation 2012 (2012): 1–22. http://dx.doi.org/10.1155/2012/309728.

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A synthesis method to design multielement antennas with couplings is presented. The main objective is to perform a rigorous determination of the electromagnetic characteristics involved in the design, especially with arrays of moderate sizes. The aim is to conceive jointly and efficiently the antenna and the circuits to connect (feed distribution network, power amplifiers, reactive loads, etc.). The subsequent objective is to improve the understanding and capabilities of strongly coupled antennas. As a whole, the synthesis procedure is then applied to different antenna architectures in order to show its efficiency and versatility. A focus on some antenna concepts where the management of couplings is a key factor to improve the performances is presented. After describing the synthesis procedure, the first category of coupled multielement antenna studied concerns radiating arrays in linear or circular polarization. A design including couplings effects on an active array is also presented. Then, the method is applied to parasitic antenna arrays and a specific investigation on reflectarray antenna is performed as they can be considered as a particular case of parasitic arrays.

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Golubev, V., V. Pashkevich, and M. Protsenko. "Development and Experimental Study of APAA HF-Band with Controlled Radiation Pattern." Proceedings of Telecommunication Universities 6, no. 1 (2020): 50–59. http://dx.doi.org/10.31854/1813-324x-2020-6-1-50-59.

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There is a promising direction in the antenna field design of a stationary transmitting radio center short-wavelength range is the use of active phased array antennas with spatial power addition and a controlled directional pattern. The article considers the algorithm for calculating the V shaped antenna as a basic element of antenna array, apart from that it considers calculation of the four-element antenna array based on the V shaped antenna. This paper presents the track tests results to estimate the power increment depending on the operating elements in the antenna array, as well as horizontal controllability results.

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Abdipour, Mahmoud, Gholamreza Moradi, and Reza Sarraf Shirazi. "Ultra-low noise active microstrip antenna." International Journal of Microwave and Wireless Technologies 6, no. 5 (December 17, 2013): 515–20. http://dx.doi.org/10.1017/s1759078713001074.

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An active receiving antenna for Radio Navigation and Radio Positioning applications in S-band frequency is designed and fabricated. In this active antenna, the amplifier is integrated with the radiator which is a rectangular patch antenna. This patch antenna is analyzed with full-wave momentum method. With the developed design routine, ultra-low noise active receiving antenna can be realized. The ADS software and its full-wave Momentum is used for simulation. The experimental results show good agreement with the simulation results.

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Guo, Linyan, Ming Deng, Qisheng Zhang, Xinyue Zhang, and Zhenzhong Yuan. "Dual-Polarized On-Chip Antenna for 300 GHz Full-Duplex Communication System." International Journal of Antennas and Propagation 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/2837629.

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This paper presents a novel design of compact orthogonally polarized on-chip antenna to realize 300 GHz full-duplex communication system with high isolation. It consists of a dipole antenna for horizontal polarization and a disk-loaded monopole antenna for vertical polarization. They are in good cross-polarization state with more than 90 dB of self-interference suppression and then can be used to achieve good isolation between transmitting and receiving antennas. In addition, two dual-polarized antennas have been adopted in two separated transceivers to study their isolation performance. Furthermore, this compact antenna only occupies an active area of 390 μm × 300 μm × 78 μm and can be used for multiple-input multiple-output application as well.

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Wang, Congsi, Yan Wang, Xiaodong Yang, Wei Gao, Chao Jiang, Lu Wang, Yiqun Zhang, and Meng Wang. "Effect of Randomness in Element Position on Performance of Communication Array Antennas in Internet of Things." Wireless Communications and Mobile Computing 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/6492143.

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As a critical component for wireless communication, active phased array antennas face the restrictions of creating effective performance with the effect of randomness in the position of the array element, which are inevitably produced in the manufacturing and operating process of antenna. A new method for efficiently and effectively evaluating the statistic performance of antenna is presented, with consideration of randomness in element position. A coupled structural-electromagnetic statistic model for array antenna is proposed from the viewpoint of electromechanical coupling. Lastly, a 12×12 planar array is illustrated to evaluate the performance of antenna with the saddle-shaped distortion and random position error. The results show that the presented model can obtain the antenna performance quickly and effectively, providing an advantageous guidance for structural design and performance optimization for array antennas in wireless application.

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Naranjo-Hernández, David, Javier Reina-Tosina, and Laura M. Roa. "Lessons Learned about the Design and Active Characterization of On-Body Antennas in the 2.4 GHz Frequency Band." Sensors 20, no. 1 (December 31, 2019): 224. http://dx.doi.org/10.3390/s20010224.

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This work addresses the design and experimental characterization of on-body antennas, which play an essential role within Body Sensor Networks. Four antenna designs were selected from a set of eighteen antenna choices and finally implemented for both passive and active measurements. The issues raised during the process of this work (requirements study, technology selection, development and optimization of antennas, impedance matching, unbalanced to balanced transformation, passive and active characterization, off-body and on-body configurations, etc.) were studied and solved, driving a methodology for the characterization of on-body antennas, including transceiver effects. Despite the influence of the body, the antennas showed appropriate results for an in-door environment. Another novelty is the proposal and validation of a phantom to emulate human experimentation. The differences between experimental and simulated results highlight a set of circumstances to be taken into account during the design process of an on-body antenna: more comprehensive simulation schemes to take into account the hardware effects and a custom design process that considers the application for which the device will be used, as well as the effects that can be caused by the human body.

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Pashkevich, V., V. Golubev, and M. Protsenko. "Modeling and Calculation Characteristics of APAA HF-Band Based on Whip Antennas." Proceedings of Telecommunication Universities 7, no. 1 (March 31, 2021): 81–92. http://dx.doi.org/10.31854/1813-324x-2021-7-1-81-92.

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When designing the antenna field of a stationary HF transmitting radiocenter, it is necessary to provide for reserving ground-based symmetrical antennas operating on round-the-clock radio directions with backup, fast-deployable antenna systems. As such antennas, it is proposed to use asymmetric vertical dipoles, active phased antenna arrays (APAA) based on them with a controlled directional pattern. This article considers methods for calculating such systems, a method is developed for determining the phase relationships of currents at the inputs of APAR elements, taking into account its placement and functioning on a real object. The results of route tests of single antennas and APAA on a radio link with a length of 650 km are presented.

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Gupta, Ravi Dutt, and Manoj Singh Parihar. "Dual/wideband hybrid DRA with reconfigurable operation." International Journal of Microwave and Wireless Technologies 9, no. 2 (November 2, 2015): 387–94. http://dx.doi.org/10.1017/s1759078715001580.

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In this paper, a rectangular dielectric resonator antenna (DRA) with a parasitic gap-coupled microstrip resonator (MSR) is investigated; analytically, and experimentally. The proposed antenna uses an open-ended half-wavelength MSR patch as a hybrid radiator. Radiating modes are identified for both the radiators. Two separate and fully independent modes are merged together to get an enhanced bandwidth. The antenna can offer three modes of operation, mode 1 (only DRA is active), mode 2 (only MSR is active), and the mode 3 (both DRA and MSR are active). In mode 3, the antenna offers a single wideband operation with ≈11% bandwidth by merging modes 1 and 2 with a broadside radiation pattern. Two switches are proposed to realize the three modes of operation. A p–i–n diode is utilized as switching element in simulations. Multiple antennas have been fabricated using a small metal strip as a switch to validate the proposal. Analytical, simulated, and measured results are found in harmony. A parametric study is done to describe the antenna characteristics. An approximate lumped element model is also extracted and presented.

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Jiang, Xiangjun, Fengqun Pan, Yesen Fan, Jingli Du, Mingbo Zhu, and Zhen Chen. "Active Adjustment of Surface Accuracy for a Large Cable-Net Structure by Shape Memory Alloy." Materials 12, no. 16 (August 16, 2019): 2619. http://dx.doi.org/10.3390/ma12162619.

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The high surface accuracy design of a cable-net antenna structure under the disturbance of the extremely harsh space environment requires the antenna to have good in-orbit adjustment ability for surface accuracy. A shape memory cable-net (SMC) structure is proposed in this paper and believed to be able to improve the in-orbit surface accuracy of the cable-net antenna. Firstly, the incremental stiffness equation of a one-dimensional bar element of the shape memory alloy (SMA) to express the relationship between the force, temperature and deformation was effectively constructed. Secondly, the finite element model of the SMC antenna structure incorporated the incremental stiffness equation of a SMA was established. Thirdly, a shape active adjustment procedure of surface accuracy based on the optimization method was presented. Finally, a numerical example of the shape memory cable net structure applied to the parabolic reflectors of space antennas was analyzed.

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31

Mun, Byeonggwi, Yonghyun Yoon, Hyunwoo Lee, Hark-Yong Lee, and Byungje Lee. "A Compact Dual-Band RFID Tag Antenna Mountable on Metallic Objects." International Journal of Antennas and Propagation 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/131908.

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A compact (50 × 50 × 4 mm3) dual-band radio frequency identification (RFID) tag antenna mountable on metallic objects is proposed for the ultra-high frequency (UHF) band (917∼923.5 MHz) and the microwave (MW) band (2.4∼2.45 GHz). With the proximity-coupled feed loop, the proposed antenna consists of two symmetric planar inverted-F antenna (PIFA) elements for the UHF band passive tag and a meander microstrip patch antenna for the MW band active tag. The performance of the proposed antenna is verified by mounting it on the different sizes of the metallic object. Furthermore, the passive tag antenna in the UHF band furthermore may be used for energy harvesting techniques to improve the lifetime of the active tag in the MW band. The measured maximum read range is 5.50 m in the UHF band and 14.15 m in the MW band when the proposed tag antenna is mounted on the metallic objects. The total efficiency for all operating frequency bands is higher than 50%. High isolation (>12 dB) between tag antennas in the UHF band and the MW band is achieved.

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32

Gavrilova, S. E., A. N. Gribanov, G. F. Moseychuk, and A. I. Sinani. "Features of excitation reconstruction in flat multielement phased antenna array face using dynamic directional patterns." Journal of «Almaz – Antey» Air and Space Defence Corporation, no. 4 (December 30, 2017): 32–39. http://dx.doi.org/10.38013/2542-0542-2017-4-32-39.

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The study focuses on reconstructing the amplitude-phase distribution of flat multielement passive and active phased antenna arrays with the use of dynamic radiation patterns, measured with electronical scanning without mechanical rotations and antenna movements. The paper describes the measurement settings of dynamic radiation patterns, necessary for reconstructing the amplitude-phase distribution. Findings of the research show that to reconstruct the amplitude-phase distribution according to dynamic radiation diagrams, there is no need for increased computational resources due to the use of Fourier transformation algorithms. After the method was experimentally verified on the specific samples of active phased antenna arrays, its high efficiency was established. The paper gives the examples of reconstructing the amplitude-phase distribution from dynamic radiation patterns in the presence of malfunctions in active phased array antennas.

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Stark, Alexander, Benjamin Rohrdantz, Ulf Johannsen, and Arne F. Jacob. "In-situ probes for patch antenna array calibration." International Journal of Microwave and Wireless Technologies 3, no. 3 (April 4, 2011): 273–80. http://dx.doi.org/10.1017/s1759078711000316.

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A novel calibration network for patch antennas is proposed. We introduce magnetically coupled in-situ probes, which excite the fundamental patch mode. In that way, finite array effects and mutual coupling are taken into account, providing the opportunity for accurate online calibration of active antenna terminals. The specific advantages of the approach are demonstrated for linearly polarized patch antennas. Realization aspects of the multilayer antenna are discussed and the effect of some fabrication imperfections are investigated. Measured S-parameters as well as radiation simulation results of a single patch with the integrated probes are presented. Based on simulation of antenna arrays with in-situ probes the calibration accuracy is given in theory.

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Jagodzińska, Katarzyna, Stanisław Dziura, and Maciej Walkowiak. "Active Impedance Matching." Solid State Phenomena 210 (October 2013): 3–8. http://dx.doi.org/10.4028/www.scientific.net/ssp.210.3.

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Electrically small antenna suffer from the high Q impedance such as narrow bandwidth and poor gain. To improve them, passive impedance matching is often used but it is restricted to a Bode-Fano limit. To skip it, active matching incorporating non-Foster circuits can provide a good solution. Using non-Foster theory, in this paper an active reactance circuit (ARC) design is proposed for application to electrically small antenna prototypes.

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Kim, Joon-Il, Won-Taek Lee, Jin-Woo Chang, and Yong Jee. "Design of Active Antenna Diplexers Using UWB Planar Monopole Antennas." Journal of Korean Institute of Electromagnetic Engineering and Science 18, no. 9 (September 30, 2007): 1098–106. http://dx.doi.org/10.5515/kjkiees.2007.18.9.1098.

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36

Lyubchenko, Vladimir E., Eugeny O. Yunevich, Valery I. Kalinin, Viktor D. Kotov, and Sergey A. Telegin. "ACTIVE MICROSTRIP ANTENNAS AND ANTENNA ARRAYS WITH FIELD-EFFECT TRANSISTORS." Radioelectronics. Nanosystems. Information Technologies. 7, no. 1 (June 2015): 3–14. http://dx.doi.org/10.17725/rensit.2015.07.003.

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37

Sewoong Kwon, Byoung Moo Lee, Young Joong Yoon, Woo Young Song, and Jong-Gwan Yook. "A harmonic suppression antenna for an active integrated antenna." IEEE Microwave and Wireless Components Letters 13, no. 2 (February 2003): 54–56. http://dx.doi.org/10.1109/lmwc.2003.808716.

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38

Dong-Hyuk Choi and Seong-Ook Park. "A varactor-tuned active-integrated antenna using slot antenna." IEEE Antennas and Wireless Propagation Letters 4 (2005): 191–93. http://dx.doi.org/10.1109/lawp.2005.850799.

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39

Bonnet, B., R. Chiniard, H. Legay, D. Nevo, P. Monfraix, O. Vendier, P. Couderc, and J. L. Cazaux. "Use of 3D Packaging Technology for Satellite Active Antennas Front-ends." International Symposium on Microelectronics 2012, no. 1 (January 1, 2012): 000554–60. http://dx.doi.org/10.4071/isom-2012-wa14.

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Multi-Chip Module Vertical (MCM-V) technology, also called 3D packaging technology, enables the realization of a compact and low loss integrated feed for active antennas in Ka band. The active devices can be located in the vicinity of the radiating element, which reduces dramatically the volume and complexity of the antenna front-end for future architectures with more than a hundred beams in Ka band. This paper deals with the optimization of 3D packaging technology to reach the requirements of 30GHz microwave modules for space applications. The technological developments that have been led on the design and the assembly processes are detailed. The measurement results of an integrated feed module in radiation are given and the circuit designed to optimize the signal-to-noise ratio of the front-end for receiving antennas is characterized. The performance is as good as for an optimized planar front-end with a waveguide access for a much more compact module, especially in terms of footprint in an antenna array. These results successfully position 3D packaging as a disruptive technology for future space and telecom subsystems.

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40

Kaneko, Makoto, and Naohiro Ueno. "Basic Study on Active Antenna." Journal of the Robotics Society of Japan 13, no. 1 (1995): 149–56. http://dx.doi.org/10.7210/jrsj.13.149.

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Kaneko, Makoto, Yoshiharu Bessho, and Toshio Tsuji. "Tracing Type Artificial Active Antenna." Journal of the Robotics Society of Japan 18, no. 8 (2000): 1173–79. http://dx.doi.org/10.7210/jrsj.18.1173.

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KANAYAMA, Naoki, Makoto KANEKO, and Toshio TSUJI. "Vision Based Artificial Active Antenna." Transactions of the Society of Instrument and Control Engineers 32, no. 9 (1996): 1321–28. http://dx.doi.org/10.9746/sicetr1965.32.1321.

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UENO, Naohiro, and Makoto KANEKO. "Self-Excited Dynamic Active Antenna." Transactions of the Society of Instrument and Control Engineers 33, no. 11 (1997): 1053–58. http://dx.doi.org/10.9746/sicetr1965.33.1053.

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44

Ueno, Naohiro, and Makoto Kaneko. "Self-excited Dynamic Active Antenna." Advanced Robotics 11, no. 7 (January 1996): 725–40. http://dx.doi.org/10.1163/156855398x00406.

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45

Osman, Onur. "Variable active antenna spatial modulation." IET Microwaves, Antennas & Propagation 9, no. 15 (December 2015): 1816–24. http://dx.doi.org/10.1049/iet-map.2014.0683.

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46

Gautam, A. K., and B. R. Vishvakarma. "Frequency agile active microstrip antenna." Microwave and Optical Technology Letters 49, no. 2 (2006): 431–34. http://dx.doi.org/10.1002/mop.22174.

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Immoreev, I. "Active transmitting phased antenna arrays." IEEE Transactions on Aerospace and Electronic Systems 41, no. 2 (April 2005): 407–20. http://dx.doi.org/10.1109/taes.2005.1468737.

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48

Fralich, R., and J. Litva. "Beam-steerable active array antenna." Electronics Letters 28, no. 2 (1992): 184. http://dx.doi.org/10.1049/el:19920114.

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Wu, X. D., K. Leverich, and K. Chang. "Novel FET active patch antenna." Electronics Letters 28, no. 20 (1992): 1853. http://dx.doi.org/10.1049/el:19921185.

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Leverich, W. K., X. D. Wu, and K. Chang. "New FET active notch antenna." Electronics Letters 28, no. 24 (1992): 2239. http://dx.doi.org/10.1049/el:19921439.

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Journal articles on the topic 'Active antenna'

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