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1
Ma, Fangyan, Xinpei Zhang, Yuanyuan Yin, Hang Yin, Chao Song, and Liqing Zhao. "Low-Cost Lens Antenna Design for Microwave Moisture Detection." International Journal of Antennas and Propagation 2022 (August 28, 2022): 1–12. http://dx.doi.org/10.1155/2022/3883786.
Повний текст джерелаАнотація:
In this study, a novel Vivaldi antenna with dimensions of 100 mm × 85 mm × 1.6 mm, designed for a moisture measurement system, is built to enhance the gain of conventional Vivaldi antennas in the low-frequency band to suit the needs of moisture detection. The fence structure and choke slot are modified to enhance the antenna’s radiation properties in the low-frequency band, and simulation is performed to determine how different structural parameters affect the antenna’s performance. The results show that in the frequency band of 5-6 GHz, the voltage standing-wave ratio (VSWR) of the antenna is less than 2, and the gain at 5.8 GHz reaches 16.2 dBi after installing the lens. Compared with conventional unmodified Vivaldi antennas, the gain at 5.8 GHz increases by approximately 6.11 dBi. The antenna is then processed and measured, and the measured results are in good agreement with the simulated results; hence, the antenna can be widely used in the field of moisture detection.
2
Huang, Denghui, Hu Yang, Yuqing Wu, and Fei Zhao. "An X-Band Dual-Polarized Vivaldi Antenna with High Isolation." International Journal of Antennas and Propagation 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/3281095.
Повний текст джерелаАнотація:
An X-band dual-polarized Vivaldi antenna with high isolation is proposed. The procedure of this antenna design includes the conventional Vivaldi antenna with regular slot edge (RSE), the dual-polarized Vivaldi antenna with two Vivaldi antennas which have different feeding point positions in a cross-shaped form, and the two Vivaldi antennas with a galvanic contact in soldering point. By applying the RSE, it reduced the dimensions of the Vivaldi antenna and improved its radiation performance. The modified antenna is fabricated and measured. The measured results show that S11<-10 dB at the entire X-band for the two Vivaldi antennas. The isolation (S21) between the two feeding ports, which has been improved by applying the different feeding point positions and the galvanic contact in soldering point, is better than 34 dB at X-band. In addition, the cross-polarized discrimination is better than 21 dB for the two Vivaldi antennas, and the measured results also include the gain of two Vivaldi antennas.
3
Song, Li Zhong, Huan Feng Hong, and Jing Hong Xue. "Design and Performance Simulation of Two Kinds of Antipodal Vivaldi Antennas for Wide Band Radar Systems." Applied Mechanics and Materials 170-173 (May 2012): 2893–98. http://dx.doi.org/10.4028/www.scientific.net/amm.170-173.2893.
Повний текст джерелаАнотація:
The Vivaldi antennas are widely used in many wide band electronic systems for its good performances. This paper designed and simulated two kinds of Vivaldi antennas for wide band passive radar applications, which are the antipodal Vivaldi antenna fed by strip line and antipodal Vivaldi antenna fed by microstrip line. The specific design parameters and the radiation performances of each kind of vivaldi antenna are provided over the operating frequency range of 3GHz to 11GHz. Furthermore a circular antenna array with six Vivaldi antenna elements fed by microstrip lines was also simulated to obtain its radiation performances over the operating frequency range of 3GHz to 8GHz. The simulation results demonstrate the designed Vivaldi antennas have acceptable performances of voltage standing wave ratio (VSWR), patterns and gains, so they can be used in practical wide band radars.
4
Sonkki, Marko, Sami Myllymäki, Jussi Putaala, Eero Heikkinen, Tomi Haapala, Harri Posti, and Heli Jantunen. "Dual Polarized Dual Fed Vivaldi Antenna for Cellular Base Station Operating at 1.7–2.7 GHz." International Journal of Antennas and Propagation 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/1304359.
Повний текст джерелаАнотація:
The paper presents a novel dual polarized dual fed Vivaldi antenna structure for 1.7–2.7 GHz cellular bands. The radiating element is designed for a base station antenna array with high antenna performance criteria. One radiating element contains two parallel dual fed Vivaldi antennas for one polarization with 65 mm separation. Both Vivaldi antennas for one polarization are excited symmetrically. This means that the amplitudes for both antennas are equal, and the phase difference is zero. The orthogonal polarization is implemented in the same way. The dual polarized dual fed Vivaldi is positioned 15 mm ahead from the reflector to improve directivity. The antenna is designed for -14 dB impedance bandwidth (1.7–2.7 GHz) with better than 25 dB isolation between the antenna ports. The measured total efficiency is better than -0.625 dB (87%) and the antenna presents a flat, approximately 8.5 dB, gain in the direction of boresight over the operating bandwidth whose characteristics promote it among the best antennas in the field. Additionally, the measured cross polarization discrimination (XPD) is between 15 and 30 dB and the 3 dB beamwidth varies between 68° and 75° depending on the studied frequency.
5
Ghimire, Jiwan, Feyisa Debo Diba, Ji-Hoon Kim, and Dong-You Choi. "Vivaldi Antenna Arrays Feed by Frequency-Independent Phase Shifter for High Directivity and Gain Used in Microwave Sensing and Communication Applications." Sensors 21, no. 18 (September 11, 2021): 6091. http://dx.doi.org/10.3390/s21186091.
Повний текст джерелаАнотація:
This paper describes a novel feed system for compact, wideband, high gain six-slot Vivaldi antenna arrays on a single substrate layer using a unique combination of power splitters based on binary T-junction power splitter topology, frequency-independent phase shifter, and a T-branch. The proposed antenna system consists of six Vivaldi antennas, three on the left, and three on the right arm. Each arm connects with T-junction power divider splitter topology, given that the right arm is linked through a frequency-independent phase shifter. Phase shifters ensure that the beam is symmetrical without splitting in a radiating plane so that highly directive radiation patterns occur. The optimal return losses (S-parameters) are well enriched by reforming Vivaldi’s feeding arms and optimizing Vivaldi slots and feeds. A novel feature of our design is that the antenna exhibits the arrangements of a T-junction power splitter with an out-of-phase feeding mechanism in one of the arms, followed by a T-branching feeding to even arrays of proper Vivaldi antenna arrangement contributing high realized gain and front-to-back ratio up to 14.12 dBi and 23.23 dB respectively applicable for not only ultra-wideband (UWB) application, also for sensing and position detecting. The high directivity over the entire UWB frequency band in both higher and lower frequency ranges ensures that the antenna can be used in microwave through-wall imaging along with resolution imaging for ground penetration radar (GPR) applications. The fabricated antenna parameters are in close agreement with the simulated and measured results and are deployed for the detection of targets inside the voids of the concrete brick.
6
Ren, Jinjing, Hezhihan Fan, Qi Tang, Zhongyuan Yu, Yang Xiao, and Xiang Zhou. "An Ultra-Wideband Vivaldi Antenna System for Long-Distance Electromagnetic Detection." Applied Sciences 12, no. 1 (January 5, 2022): 528. http://dx.doi.org/10.3390/app12010528.
Повний текст джерелаАнотація:
Enlarging or reducing the antenna beam width of antennas can improve the positioning capability of detection systems. A miniaturized and easily fabricated ultra-wideband (UWB) antenna system for long-distance electromagnetic detection is proposed in this article. Two ultra-wideband Vivaldi antennae were designed. One was the transmitting antenna with a beam width of 90° or above, the other was a narrow beam antenna array with beam width less than 10°, as a receiving antenna. Both proposed antennae feature broadside gain diagrams with stable radiation patterns and wideband impedance matching in the frequency range between 2.5 GHz and 4 GHz. After detecting their frequency and time-domain behaviors, the detection system can achieve measurements covering a radius of 30 m.
7
İlarslan, Mustafa, A. Serdar Türk, Salih Demirel, M. Emre Aydemir, and A. Kenan Keskin. "A Compact Vivaldi Shaped Partially Dielectric Loaded TEM Horn Antenna for UWB Communication." International Journal of Antennas and Propagation 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/847169.
Повний текст джерелаАнотація:
Ultrawideband (UWB) antennas are of huge demand and Vivaldi antennas as well as the TEM horn antennas are good candidates for UWB applications as they both have relatively simple geometry and high gain over a wide bandwidth. The aim of this study is to design a compact antenna that achieves maximum gain over a bandwidth between 1.5 and 10.6 GHz while minimizing its size. The idea is to make use of combined respective advantages of Vivaldi and TEM horn antennas to achieve the desired goals by shaping the TEM horn antenna to look like a Vivaldi antenna. The antenna structure is modified by a dielectric load in the center to increase the gain bandwidth. It is placed in a surrounding box made of PEC material to reduce the undesired side lobes and to obtain more directive radiation pattern. The simulations are performed by using the CST STUDIO SUITE electromagnetic (EM) simulation software and they are later verified by the actual measurements. The Vivaldi shaped partially dielectric loaded (VS-PDL) TEM horn antenna is proposed as a compact UWB antenna for systems using the newly established UWB band and also for the communication systems of popular bands like ISM, Wi-Fi, and GSM.
8
MARUDDANI, BASO, EFRI SANDI EFRI SANDI, and MUHAMMAD FADHIL NAUFAL SALAM. "Perancangan dan Optimasi Antena Vivaldi pada Sistem Radar Penembus Permukaan (Ground Penetrating Radar)." ELKOMIKA: Jurnal Teknik Energi Elektrik, Teknik Telekomunikasi, & Teknik Elektronika 7, no. 1 (January 24, 2019): 151. http://dx.doi.org/10.26760/elkomika.v7i1.151.
Повний текст джерелаАнотація:
ABSTRAKAntena Vivaldi merupakan salah satu jenis antena yang diimplementasikan pada radar penembus permukaan (Ground Penetrating Radar, GPR). GPR adalah salah satu metode non-destructive testing yang biasa digunakan untuk mengetahui kondisi beton/jalan raya. Penelitian ini merancang sebuah antena Vivaldi untuk digunakan pada GPR dengan frekuensi kerja 1 GHz – 2 GHz. Metode yang digunakan untuk merancang dan mengoptimasi antena Vivaldi adalah dengan mengubah beberapa parameter untuk mencapai spesifikasi yang diinginkan. Parameter tersebut antara lain lebar antena, panjang antena dan tapered slot. Optimasi yang dilakukan tetap memperhatikan pola radiasi antena agar tetap terarah. Hasil penelitian ini menghasilkan antena Vivaldi dengan dimensi 350x300 mm dengan return loss di bawah -10 dB pada rentang frekuensi 1 GHz – 2 GHz. Hasil penelitian juga menunjukkan bahwa perubahan nilai parameter lebar antena dan tapered slot menggeser frekuensi kerja antena secara signifikan.Kata kunci: Ground Penetrating Radar, Vivaldi, return loss, parameter antena ABSTRACTThe Vivaldi antenna is one type of antenna that is implemented on Ground Penetrating Radar (GPR). GPR is one of the non-destructive testing methods commonly used to determine the condition of concrete / highway. This studyaim to design a Vivaldi antenna to be used on GPR with a working frequency of 1 GHz - 2 GHz. The method that used to design and optimize Vivaldi antennas is by changing several parameters to achieve the desired specifications. These parameters include antenna width, antenna length and tapered slot. Optimization carried out still observes the radiation pattern of the antenna to keep it directed. The results showed that 350 x 300 mm antennas with return loss below -10 dB in the frequency range of 1 GHz - 2 GHz. The results also show that changes in the parameter width of the antenna and tapered slots shift the antenna working frequency significantly.Keywords: Ground Penetrating Radar, Vivaldi, return loss, antenna parameter
9
Ghazali, Mohd Ifwat Mohd, and Premjeet Chahal. "Ultra-Wideband High Gain Vivaldi Antennas Using Additive Manufacturing." International Symposium on Microelectronics 2018, no. 1 (October 1, 2018): 000754–59. http://dx.doi.org/10.4071/2380-4505-2018.1.000754.
Повний текст джерелаАнотація:
Abstract In this paper, a low-cost fabrication technique using additive manufacturing (3D printing) is demonstrated for the fabrication of ultra-wide band (UWB) Vivaldi antennas. In communications, UWB antennas are required that have high gain and wide bandwidth (3.1 GHz to 10.6 GHz) enabling high-data rates and efficient use of frequency spectrum. 3D printing has evolved into an important technology that allows rapid and simple fabrication method for printing antennas, and other components. Two different Vivaldi antennas designs (i) Vivaldi with a slot line, and (ii) Corrugated Vivaldi are presented. The fabricated antennas have a wide bandwidth of 14 GHz and a high gain of 10 dBi. For example, the corrugated antenna exploits the capability of 3D printing to incorporate slots in the design that aids in low frequency matching with increased gain.
10
Liu, C., A. Yan, C. Yu, and T. Xu. "Improvement on a 2 × 2 Elements High-Gain Circularly Polarized Antenna Array." International Journal of Antennas and Propagation 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/252717.
Повний текст джерелаАнотація:
A novel antipodal Vivaldi antenna with tapering serrated structure at the edges is proposed. Compared with traditional Vivaldi antennas without serrated structure, the gain of the designed antenna is significantly improved in the desired frequency band (4.5–7.5 GHz). In addition, a 2 × 2 Vivaldi antenna array with an orthorhombic structure is designed and fabricated to achieve a circular polarization (CP) characteristic. With this configuration, the 3 dB axial ratio bandwidth of the array reaches about 42% with respect to the center frequency of 6 GHz and a high gain is achieved as well. The novel Vivaldi antenna and CP antenna array both have ultrawide band (UWB) and high-gain characteristics, which may be applied to the field of commercial communication, remote sensing, and so forth.
11
Hall, Natasha Antoinette, Johann Wilhelm Odendaal, and Johan Joubert. "A Wideband Feed Network for Vivaldi Antenna Arrays." International Journal of Antennas and Propagation 2022 (September 10, 2022): 1–10. http://dx.doi.org/10.1155/2022/1496851.
Повний текст джерелаАнотація:
A wideband feed network for a Vivaldi antenna array is presented. A limitation of current wideband antenna arrays is the bandwidth of either the feed network or the antenna element. The proposed antenna array consists of four wideband Vivaldi antennas fed with an improved wideband feed network to extend the useable bandwidth of the array. The proposed feed network consists of coplanar waveguide-to-slotline-to-microstrip line transitions. The feed network has a single coplanar waveguide input and four microstrip line output ports. The feed network achieved uniform amplitude and phase balance and an impedance bandwidth of 160% from 1 GHz to 9 GHz. The feed network was used in a uniform linear antenna array to feed four Vivaldi antenna elements. The Vivaldi antenna array achieved stable radiation patterns from 1.3 GHz to 8 GHz, resulting in a useable bandwidth of 144%. The antenna array has a minimum gain of 8 dBi and a maximum of 13.8 dBi within the frequency band. Results for a prototype Vivaldi antenna array, measured in a compact antenna test range, are presented and compared to simulated results from CST Studio Suite.
12
El Swiefy, Bassant, Mohamed Ahmed, Hala El Sadek, and Wagdy Anis. "Novel RFID Conformal Tag Antennas for Liquid Level Detection Applications." Applied Computational Electromagnetics Society 35, no. 10 (December 8, 2020): 1255–63. http://dx.doi.org/10.47037/2020.aces.j.351020.
Повний текст джерелаАнотація:
Detection of liquid level in large tanks is presented in this paper. The liquid level is detected using a transmitter and RFID tag antennas as a receiver. The transmitter antenna is a Vivaldi with wide bandwidth from 0.5 GHz to 3 GHz. The Vivaldi antenna is fabricated on FR4 with 𝜀𝑟 = 4.3 and thickness of 0.8 mm. Two conformal RFID tag antennas are used as receiver antennas. The conformal antenna is placed on Rogers Ultram 3850 flexible substrates with 𝜀𝑟 = 2.9 and a thickness of 0.1016 mm. The conformal antenna is designed to set on a cylindrical tank made from PVC material. The first tag works at 0.9 GHz and the second tag works at 2.45 GHz. Water and Oil are used as liquids for testing. The antennas are simulated using CST microwave studio simulator Ver.14. The system is also fabricated and measured. Good agreement is achieved between simulated and measured results.
13
Parveen, Farhana, and Parveen Wahid. "Design of Miniaturized Antipodal Vivaldi Antennas for Wideband Microwave Imaging of the Head." Electronics 11, no. 14 (July 20, 2022): 2258. http://dx.doi.org/10.3390/electronics11142258.
Повний текст джерелаАнотація:
Many wideband applications, e.g., microwave imaging of the head, require low-frequency (~1–6 GHz) operation using small antennas. Vivaldi antennas are extensively used in multifarious wideband applications; however, the physical dimensions of the antenna become very large for covering low-frequency bands. Hence, the miniaturization of Vivaldi antennas, while maintaining proper matching and radiation characteristics, is essential for these applications. In this work, two miniaturized Vivaldi antennas are proposed, and several miniaturization techniques are presented for reducing the size of the antennas without the need for being immersed into any matching liquid, while maintaining desired performance. The novelty of the designs lies in the use of two half-cut superstrates, which help in achieving low-frequency operation with end-fire radiation. Two prototype antennas are fabricated, and the performances of the antennas are analyzed from both simulation and measurement results. The antennas show an FBW of 45.26% and 95.9% with a gain of ~1.9–5.2 dB and ~1.5–5.5 dB, respectively, while having a radiation efficiency above 80% within the resonant bandwidth. A comparison of the proposed antennas with several other state-of-the-art Vivaldi antennas is included to demonstrate the viability of the proposed antennas in achieving the desired performance with comparatively small dimensions.
14
Altintas, Gulsah, Ibrahim Akduman, Aleksandar Janjic, and Tuba Yilmaz. "A Novel Approach on Microwave Hyperthermia." Diagnostics 11, no. 3 (March 10, 2021): 493. http://dx.doi.org/10.3390/diagnostics11030493.
Повний текст джерелаАнотація:
Microwave hyperthermia (MH) requires the selective focusing of microwave energy on the targeted region while minimally affecting the healthy tissue. Emerging from the simple nature of the linear antenna arrays, this work demonstrates focusing maps as an application guide for MH focusing by adjusting the antenna phase values. The focusing of the heating potential (HP) on different density breast models is performed via the proposed method using Vivaldi antennas. The effect of the tumor conductivity on the focusing is discussed. As a straightforward approach and utilizing the Vivaldi antennas, the system can be further combined with MH monitoring application.
15
Qashlan, Ayman M., Rabah W. Aldhaheri, and Khalid H. Alharbi. "A Modified Compact Flexible Vivaldi Antenna Array Design for Microwave Breast Cancer Detection." Applied Sciences 12, no. 10 (May 12, 2022): 4908. http://dx.doi.org/10.3390/app12104908.
Повний текст джерелаАнотація:
In this paper, a compact, flexible Vivaldi antenna is designed, and an array of nine identical antennas of this type is used as a microwave breast imaging model to detect cancerous tumors in the multilayers phantom model presented in this paper. The nine-antenna array is used to measure the backscattering signal of the breast phantom, where one antenna acts as a transmitter and the other eight antennas act as receivers of the scattered signals. Then, the second antenna is used as a transmitter and the other antennas as receivers, and so on till we have gone through all the antennas. These collected backscattered signals are used to reconstruct the image of the breast phantom using software called “Microwave Radar-based Imaging Toolbox (MERIT)”. From the reconstructed image, the tumor inside the breast model can be identified and located. Different tumor sizes in different locations are tested, and it is found that the locations can be determined irrespective of the tumor size. The proposed modified Vivaldi antenna has a very compact size of 25 × 20 × 0.1 mm3 and has a different geometry compared with conventional Vivaldi antennas. The first version of the antenna has two resonant frequencies at 4 and 9.4 GHz, and because we are interested more in the first band, where it gives us sufficient resolution, we have notched the second frequency by etching two slots in the ground plane of the antenna and adding two rectangular parasitic elements on the radiating side of the antenna. This technique is utilized to block the second frequency at 9.4 GHz, and, as a result, the bandwidth of the first resonant frequency is enhanced by 20% compared with the first design bandwidth. The modified antenna is fabricated on Polyimide flexible material 0.1 mm thick with a dielectric constant of 3.5 using a standard PCB manufacturing process. The measured performance of this antenna is compared with the simulated results using the commercially available simulation software Ansoft HFSS, and it is found that the measured results and the simulated results are in good agreement.
16
Jiang, Ming, Li Zhong Song, Xin Tong, and Liang Fang. "Experimental Research on an Antipodal Vivaldi Antenna with Wide Band." Advanced Materials Research 631-632 (January 2013): 1022–25. http://dx.doi.org/10.4028/www.scientific.net/amr.631-632.1022.
Повний текст джерелаАнотація:
The Vivaldi antenna is a kind of wide band antenna, which is widely used in many wide band electronic systems. This paper designed and fabricated a specific antipodal Vivaldi antenna (AVA) for practical application. The operating frequency range of fabricated AVA is from 2 GHz to 11GHz. The length and width of the fabricated AVA are 92.7millimeter and 110.4millimeter, respectively. A practical AVA was fabricated according to simulation parameters. The experimental results of the AVA are provided and analyzed. For the fabricated AVA, the measured average voltage standing wave ratio (VSWR) is 2 and gains are higher than 0 dB within the operating frequency range. Meanwhile, the wide beam performances are also observed. The experimental research on the AVA can be as a technical reference for the design and implementation of other Vivaldi antennas.
17
Zhukov, A. N., R. V. Zhukov, and S. S. Rozhkov. "Prospects of combined antenna systems in onboard electronic protection systems of aircraft." Journal of «Almaz – Antey» Air and Space Defence Corporation, no. 4 (December 30, 2017): 40–45. http://dx.doi.org/10.38013/2542-0542-2017-4-40-45.
Повний текст джерелаАнотація:
The study compares two designs of antenna units in terms of reducing the coupling ratio between the transmitting and receiving antennas. The first design is the original transceiver antenna unit of an electronic countermeasure aircraft, which contains two transmitter antennas close to each other in a shared compartment and a receiver antenna in a separate compartment behind a solid screen with bevelled edges. The second design is an upgraded antenna unit of a compact electronic countermeasure station, in which each antenna is located in its own compartment formed by a cross-shaped divider; additional measures have also been taken to improve the modulus of the coupling ratio between antennas. Both antenna unit designs use the same broadband Vivaldi antennas.
18
Salem Hesari, Sara, and Jens Bornemann. "Antipodal Vivaldi Antenna Arrays Fed by Substrate Integrated Waveguide Right-Angled Power Dividers." Applied Sciences 8, no. 12 (December 14, 2018): 2625. http://dx.doi.org/10.3390/app8122625.
Повний текст джерелаАнотація:
This paper describes a novel feed system for compact antipodal Vivaldi antenna arrays on a single layer of substrate integrated waveguide (SIW) by using SIW H-plane right-angled power dividers. The proposed antenna systems are composed of a Vivaldi array and an H-plane right-angled corner power divider which includes an over-moded waveguide section. Based on the number of antennas in the Vivaldi array, mode converter sections at K-band and Ka-band frequencies are designed, fabricated, and measured when feeding Vivaldi antenna arrays with two, three, and four antennas. Right-angled SIW power dividers are employed to obtain controllable phase distribution over the output ports which consequently controls the beam shapes of the systems. The phase relationships in the output ports are varied to obtain different pattern directions for different applications. The two-way divider system with 180-degree phase difference and three-way divider system are fabricated and measured; simulation results are presented for other designs. The measured results are in good agreement with simulations which confirms the design approach. All systems achieve good performance and meet all design goals including a return loss better than 10 dB in the operating bandwidth, gain higher than 8 dB for all systems, and radiation and polarization efficiencies higher than 80% and 98%, respectively.
19
Li, Zengrui, Xiaole Kang, Jianxun Su, Qingxin Guo, Yaoqing (Lamar) Yang, and Junhong Wang. "A Wideband End-Fire Conformal Vivaldi Antenna Array Mounted on a Dielectric Cone." International Journal of Antennas and Propagation 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/9812642.
Повний текст джерелаАнотація:
The characteristics of a novel antipodal Vivaldi antenna array mounted on a dielectric cone are presented. By employing antipodal Vivaldi antenna element, the antenna array shows ultrawide bandwidth and end-fire radiation characteristics. Our simulations show that the cone curvature has an obvious influence on the performance of the conformal antenna, in terms of both the bandwidth and the radiation patterns. The thickness and permittivity of the dielectric cone have an effect on the bandwidth of the conformal antenna. Measurement results of both single antenna and conformal antenna array show a good agreement with the simulated results. The measured conformal antenna can achieve a −10 dBS11with bandwidth of 2.2–12 GHz and demonstrate a typical end-fire radiation beam. These findings provide useful guidelines and insights for the design of wideband end-fire antennas mounted on a dielectric cone.
20
Alhawari, Adam R. H., Tale Saeidi, Abdulkarem Hussein Mohammed Almawgani, Ayman Taher Hindi, Hisham Alghamdi, Turki Alsuwian, Samer A. B. Awwad, and Muhammad Ali Imran. "Wearable Metamaterial Dual-Polarized High Isolation UWB MIMO Vivaldi Antenna for 5G and Satellite Communications." Micromachines 12, no. 12 (December 14, 2021): 1559. http://dx.doi.org/10.3390/mi12121559.
Повний текст джерелаАнотація:
A low-profile Multiple Input Multiple Output (MIMO) antenna showing dual polarization, low mutual coupling, and acceptable diversity gain is presented by this paper. The antenna introduces the requirements of fifth generation (5G) and the satellite communications. A horizontally (4.8–31 GHz) and vertically polarized (7.6–37 GHz) modified antipodal Vivaldi antennas are simulated, fabricated, and integrated, and then their characteristics are examined. An ultra-wideband (UWB) at working bandwidths of 3.7–3.85 GHz and 5–40 GHz are achieved. Low mutual coupling of less than −22 dB is achieved after loading the antenna with cross-curves, staircase meander line, and integration of the metamaterial elements. The antennas are designed on a denim textile substrate with εr = 1.4 and h = 0.5 mm. A conductive textile called ShieldIt is utilized as conductor with conductivity of 1.8 × 104. After optimizing the proposed UWB-MIMO antenna’s characteristics, it is increased to four elements positioned at the four corners of a denim textile substrate to be employed as a UWB-MIMO antenna for handset communications, 5G, Ka and Ku band, and satellite communications (X-band). The proposed eight port UWB-MIMO antenna has a maximum gain of 10.7 dBi, 98% radiation efficiency, less than 0.01 ECC, and acceptable diversity gain. Afterwards, the eight-ports antenna performance is examined on a simulated real voxel hand and chest. Then, it is evaluated and compared on physical hand and chest of body. Evidently, the simulated and measured results show good agreement between them. The proposed UWB-MIMO antenna offers a compact and flexible design, which is suitably wearable for 5G and satellite communications applications.
21
Lee, Wen-Yu, Hsin-Piao Lin, and Ding-Bing Lin. "Low-Reflection Cross Section and High-Isolation 2x2 Broadband Antenna Array for the MIMO Measurement System." MATEC Web of Conferences 232 (2018): 04054. http://dx.doi.org/10.1051/matecconf/201823204054.
Повний текст джерелаАнотація:
The author of this paper explored Vivaldi [1] [2] line theory and technology and used it as a basis to propose a Vivaldi antenna array to replace a single Vivaldi antenna. This was to achieve a dual-polarized antenna with high directivity and high isolation in the MIMO anechoic chamber, and one that is minimally affected by the environment. The operating frequency of this antenna array covers a frequency range of 0.7–6.0 GHz and is composed of four Vivaldi units with relatively high isolation between them to reduce measurement errors caused by coupling. In each unit, two identical Vivaldi antennas are connected in parallel to form the same polarization unit, and a microstrip power divider was used and the impedance matching of circular holes was performed to design this connected antenna with an ultra-wide operating frequency and the same polarization. The authors then interconnected two polarization units orthogonally at 90 degree cross to form the antenna described in this study, which has high directivity, high isolation, an ultra-wide frequency and dual polarization. During the design process, an FR4 printed circuit board (PCB) was used to effectively reduce the cross-sectional area of the antenna and reduce reflection and interference on the basis of ensuring an ultra-wide operating frequency. Additionally, the two orthogonal units of each polarized antenna unit had to work separately, and the electric field data collected from different polarization directions were sequentially transmitted to the receiver for postprocessing to satisfy the measurement requirements of the MIMO OTA anechoic chamber. In this study, SEMCAD electromagnetic simulation software was used to adjust and complete the analysis of antenna characteristics and obtain a favorable operating frequency and voltage standing wave ratio, as well as excellent isolation and radiation characteristics.
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Kurdyanto, Rachmat Agus, Nurhayati Nurhayati, Puput Wanarti Rusimamto, and Farid Baskoro. "STUDY COMPARATIVE OF ANTENNA FOR MICROWAVE IMAGING APPLICATIONS." INAJEEE Indonesian Journal of Electrical and Eletronics Engineering 3, no. 2 (August 28, 2020): 41. http://dx.doi.org/10.26740/inajeee.v3n2.p41-47.
Повний текст джерелаАнотація:
AbstractMicrowave can be applied for telecommunicaions, radar and microwave imaging. This wave has been widely used in everyday life, such as in the industrial word in the fields of robotics, microwave vision, imaging burrier objects, vehicular guidance, biomedical imaging, remote sensing, wheater radar, target tracking, and other apllications. Microwave imaging is a technology that uses electromagnetic waves at frequencies from Megahertz to Gigahertz. Utilization of microwave imaging in addition to information technology and telecommunications, this wave application can be used to process an image because of its ability to penetrate dielectric materials. The purpose of writing this article is to determine microwave imaging application, the working principle of antennas used for microwave imaging applications and antenna specifications used for microwave imaging applications. Microwave imaging research has been carried out using several different type of antennas such as vivaldi and monopole antennas. Where the signal tha is transmitted and will be exposed to the object will send a different return signal so that an image of an object will be obtained which will be processed on the computer. The working frequency of the antenna for microwave imaging applications is in a wide frequency range (UWB antenna). The antennas that are applied include the vivaldi antenna which works at a frequency of 1-11 GHz and a monopole antenna that works at a frequency 1,25-2,4 GHz for biomedical imaging applications, while for radar applications in the construction field it can use a frequency of 0,5-40 GHz.
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He, XiaoXiang, SaiSai Huang, Teng Chen, and Yang Yang. "Ladder Arrangement Method for Stealth Design of Vivaldi Antenna Array." International Journal of Antennas and Propagation 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/295767.
Повний текст джерелаАнотація:
A novel stealth design method for X-band Vivaldi antenna arrays is proposed in this paper by ladder arrangement along radiation direction. Two-element array, eight-element array, and 3 × 7-element array are investigated in this paper. S parameters, RCSs, and radiation patterns are studied, respectively. According to the ladder arrangement of Vivaldi antennas presented, 16.3 dBsm maximal RCS reduction is achieved with satisfied radiation performance. As simulated and measured, results demonstrate that the effectiveness of the presented low RCS design method is validated.
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Witriani, Findi Nur, Yahya Syukri Amrullah, Fajri Darwis, Taufiqqurrachman Taufiqqurrachman, Yusuf Nur Wijayanto, Ken Paramayudha, and Elisma Elisma. "Gain Enhancement of Double-Slot Vivaldi Antenna using Corrugated Edges and Semicircle Director for Microwave Imaging Application." Jurnal Elektronika dan Telekomunikasi 21, no. 2 (December 31, 2021): 85. http://dx.doi.org/10.14203/jet.v21.85-90.
Повний текст джерелаАнотація:
Microwave imaging, such as images for radiological inspection in the medical profession, is one of the applications utilized in ultra-wideband (UWB) frequency ranges. The Vivaldi antenna is one of the most popular antennas for this purpose. The antenna is utilized because of its simple, lightweight, and compact design, as well as its excellent efficiency and gain capabilities. In this work, we present a high-gain Vivaldi antenna for microwave imaging applications. The proposed Vivaldi antenna is designed using a double-slot structure method with the addition of corrugated edges and a semicircle director aimed at improving the gain. The antenna is designed to operate at frequencies ranging from 3.1 to 10.6 GHz. Based on the modeling findings, the suggested antenna attain a bandwidth of 7.5 GHz with operating frequencies from 3.1 GHz to 10.6 GHz for a VSWR of less than two. In comparison to a typical single slot antenna, the suggested antenna provides a substantial boost in gain performance. The increase in gain is proportional to the frequency of operation. The constructed antenna has a lower bandwidth than the simulated one, with operating frequencies of 3.5 GHz – 3.75 GHz and 4.25 – 10.89 GHz, respectively, and useable bandwidths of 250 MHz and 6.64 GHz. All these results suggest that the antenna is suitable for microwave imaging applications.
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Agustini, Rizqi, and Nurhayati Nurhayati. "Improvement of Coplanar Vivaldi Antenna Radiation Patterns with Fractal Structure for Ultra-Wideband Applications." INAJEEE Indonesian Journal of Electrical and Eletronics Engineering 4, no. 2 (November 25, 2021): 44–50. http://dx.doi.org/10.26740/inajeee.v4n2.p44-50.
Повний текст джерелаАнотація:
The need for telecommunications technology requires fast data transfer and increasing capacity. Therefore, telecommunications technology continues to be developed by creating transmitter and receiver devices that can work at Ultra-Wideband (UWB) frequencies. This study aims to design a coplanar Vivaldi antenna with a fractal structure so that the performance of the antenna radiation pattern can increase to apply UWB frequency. The conventional coplanar Vivaldi antenna, model-A, and Model-B fractal antennas are designed to see the performance of return loss values less than -10 dB, VSWR less than 2, and working frequency of 2-10 GHz. The fractal model is created with a circular repeating structure given at the edges of the antenna patch. From the simulation results, the main lobe value of the conventional Coplanar Vivaldi antenna was 5.21 dBi, the model-A fractal was 7.02 dBi, and the Model-B fractal was 7.84 dBi. The order of the best sidelobe performance at a frequency of 6 GHz is obtained for the model-A fractal of -9 dB. Beamwidth of 46 degrees and the best main lobe direction of 0 degrees is obtained for fractal model-B. By adding a fractal structure, the lobe magnitude/directivity, sidelobe level, beamwidth, and main lobe direction can be improved
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Slimi, Marwa, Bassem Jmai, Hugo Dinis, Ali Gharsallah, and Paulo Mateus Mendes. "Metamaterial Vivaldi Antenna Array for Breast Cancer Detection." Sensors 22, no. 10 (May 23, 2022): 3945. http://dx.doi.org/10.3390/s22103945.
Повний текст джерелаАнотація:
The objective of this work is the design and validation of a directional Vivaldi antenna to detect tumor cells’ electromagnetic waves with a frequency of around 5 GHz. The proposed antenna is 33% smaller than a traditional Vivaldi antenna due to the use of metamaterials in its design. It has an excellent return loss of 25 dB at 5 GHz and adequate radiation characteristics as its gain is 6.2 dB at 5 GHz. The unit cell size of the proposed metamaterial is 0.058λ × 0.054λ at the operation frequency of 5 GHz. The proposed antenna was designed and optimized in CST microwave software, and the measured and simulated results were in good agreement. The experimental study demonstrates that an array composed with the presented antennas can detect the existence of tumors in a liquid breast phantom with positional accuracy through the analysis of the minimum amplitude of Sii.
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Najafy, Vahid, and Mohammad Bemani. "Mutual-coupling reduction in triple-band MIMO antennas for WLAN using CSRRs." International Journal of Microwave and Wireless Technologies 12, no. 8 (March 19, 2020): 762–68. http://dx.doi.org/10.1017/s1759078720000215.
Повний текст джерелаАнотація:
AbstractFor the requirements of low mutual-coupling MIMO antennas for WLAN, a new complementary split-ring resonator (CSRR) unit cell is introduced in this paper. A microstrip-fed Vivaldi antenna array is designed for WLAN applications, where compact triple-band gap-complementary split-ring resonator unit cells are loaded between two antennas to examine the effect of unit cells on the rate of mutual-coupling reduction. By inserting the CSRR, the final design offered an improvement in decoupling by 8.5, 10.5, and 18 dB at 3.65, 4.9, and 5.8 GHz, respectively, compared with the reference antenna. By suppressing surface waves, antenna gain and front-to-back ratio are improved.
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Elhefnawy, Mohamed, and Frank Podd. "A Vivaldi Antenna with Improved Bandwidth and Gain." International journal of electrical and computer engineering systems 13, no. 13 (February 3, 2022): 1–7. http://dx.doi.org/10.32985/ijeces.13.1.1.
Повний текст джерелаАнотація:
In this paper, the radiation characteristics of the conventional Vivaldi antenna are improved by proposing a novel design of a Vivaldi antenna. This proposed Vivaldi antenna is excited through three slots by using the L-probe microstrip feeder. The novel design can provide higher gain and wider bandwidth compared to that of the conventional Vivaldi antenna of the same size. The CST MWS software is used to simulate the proposed Vivaldi antenna. The measured and the simulated S-parameters were compared so that the feasibility of the proposed Vivaldi antenna was validated. The measured S-parameters show that the impedance bandwidth of the proposed Vivaldi antenna was from 1.976 to 7.728 GHz, while the measured maximum gain is 4.9 dBi at the operating frequency of 3 GHz.
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Raha, Krishnendu, and K. P. Ray. "Through Wall Imaging Radar Antenna with a Focus on Opening New Research Avenues." Defence Science Journal 71, no. 5 (September 2, 2021): 670–81. http://dx.doi.org/10.14429/dsj.71.16592.
Повний текст джерелаАнотація:
This review paper is an effort to develop insight into the development in antennas for through wall imaging radar application. Review on literature on antennas for use in through wall imaging radar, fulfilling one or more requirements/specifications such as ultrawide bandwidth, stable and high gain, stable unidirectional radiation pattern, wide scanning angle, compactness ensuring portability and facilitating real-time efficient and simple imaging is presented. The review covers variants of Vivaldi, Bow tie, Horn, Spiral, Patch and Magneto-electric dipole antennas demonstrated as suitable antennas for the through wall imaging radar application. With an aim to open new research avenues for making better through wall imaging radar antenna, review on relevant compressive reflector antennas, surface integrated waveguide antennas, plasma antennas, metamaterial antennas and single frequency dynamically configurable meta-surface antennas are incorporated. The review paper brings out possibilities of designing an optimum through wall imaging radar antenna and prospects of future research on the antenna to improve radiation pattern and facilitate overall simple and efficient imaging by the through wall imaging radar.
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Kerarti, Djalal Ziani, and Fatima Zahra Marouf. "Improved Characteristics of Antipodal Vivaldi Antenna for UWBRADAR Applications." International Journal of Sensors, Wireless Communications and Control 9, no. 2 (October 25, 2019): 287–94. http://dx.doi.org/10.2174/2210327908666181102124552.
Повний текст джерелаАнотація:
Background & Objective: In this paper, a simple design of antipodal Vivaldi antenna for ultra-wideband Radar applications is presented. Methods: The antenna provided to operate across the entire UWB spectrum sins it covers a very wide frequency band from 2.43 up to 13 GHz with better return loss characteristics. In addition, the antenna offers high and flat gain in this band. The numerical designs of the antennas have been performed by using the commercially available software CST MW, which it’s printed on Taconic substrate with a dielectric constant of 4.5 and thickness 1.6 mm. Results and Conclusion: The antenna has a compact dimension of 40 × 50 mm2 achieve satisfactory impedance matching and radiation efficiency.
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Safitri, Nurlaila, Rina Pudji Astuti, and Bambang Setia Nugroho. "Switch-Beam Vivaldi Array Antenna Based On 4x4 Butler Matrix for mmWave." MATEC Web of Conferences 218 (2018): 03011. http://dx.doi.org/10.1051/matecconf/201821803011.
Повний текст джерелаАнотація:
It will be diffcult to use either omnidirectional or fixed beam antenna due to the high propagation losses caused by atmospheric absorption at mmWave for 5G mobile communication. Several studies have been conducted recently using butler matrix which is part of switchable antenna with some advantages such as simple, minimal cost, low loss, etc. Previous studies also have designed vivaldi array antenna at 28 GHz which provides a fix beam directional radiation pattern with narrow beam that requires real phase setting. However, there has been no research using vivaldi antenna with butler matrix, whereas it has some advantages such as wide bandwidth, high gain, high directivity, etc. This paper proposed 4x4 butler matrix integrated with vivaldi antenna by using phase shift of 45 . The design is developed on a single layer of Rogers RT5880 with dielectric constant 2.2 and thickness 0.254 mm. Best results of simulation were picked for overall system at 28 GHz, and the results of antenna as follows: the return loss was below -10 dB, the realized antennas gain was 10.2 dB with unidirectional radiation pattern and bandwidth antenna of 6 GHz that covers from 25 GHz to 31 GHz. The butler matrix average phase di erent between output port are -44.106°, 137.38°, -137.66°, 43.95° with phase err°r °f 0.894°, 2.38°, 2.66°, 1.06°. Antenna array that has been given di erent phase by butler matrix is able to shift radiation pattern on the input port successively with range of beam that can be achieved equal to 185o.
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Байдин, И. С., А. В. Огинов та Е. В. Паркевич. "Сверхширокополосная антенна для регистрации радиоизлучения в начальной фазе высоковольтного лабораторного атмосферного разряда". Журнал технической физики 91, № 12 (2021): 1910. http://dx.doi.org/10.21883/jtf.2021.12.51756.12-21.
Повний текст джерелаАнотація:
A compact ultra - wideband antenna, designed for the employment in the experiments on studying radio emission generated in the initial phase of the spark discharge, is presented. A flat type of antennas based on an expanding slit (Vivaldi antenna) is considered. The simulation and calculation of the antenna parameters are carried out. The results of using the antenna in laboratory experiments are demonstrated. It is shown that the generation of the highest frequency part of the radio emission spectrum coincides with the pre-breakdown stage of the discharge, before a sharp increase in the current starts.
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Фёдоров, С. М., Е. А. Ищенко, И. А. Зеленин, Е. В. Папина, Е. Д. Меньшикова, and С. И. Деревянкин. "INTERCONNECTION OF VIVALDI ANTENNAS IN THE MIMO ANTENNA ARRAY." ВЕСТНИК ВОРОНЕЖСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА, no. 6 (January 10, 2021): 108–11. http://dx.doi.org/10.36622/vstu.2020.16.6.016.
Повний текст джерелаАнотація:
Рассматривается MIMO антенная решетка, сформированная из двух антенн Вивальди, которые должны обеспечить работу в частотном диапазоне, выделенном для сетей пятого поколения - 24,25-24,65 ГГц. Для определения основных параметров антенны применялось моделирование, на основе которого были установлены основные характеристики MIMO антенной решетки: коэффициент корреляции огибающей, коэффициент усиления при разнесенном режиме, эффективность сложения. По результатам было определено, что при расстоянии между антеннами в 6,13 мм достигаются максимально возможные характеристики MIMO антенной решетки, а для стабильного функционирования достаточным является расстояние в 2,45 мм. В статье приводятся размеры исследуемой антенны, графики обратных потерь (S - параметров), диаграммы направленности, коэффициентов корреляции огибающих, коэффициента усиления при разнесенном режиме, эффективности сложения при различных расстояниях между антенными элементами. Обеспечение стабильности работы MIMO антенной решетки является важной задачей, так как все современные системы связи используют эту технологию для реализации многоканальной передачи, а следовательно, для повышения скорости передачи информации. Для определения геометрических характеристик и выполнения моделирования применялось специализированное программное обеспечение The article discusses a MIMO antenna array formed of two Vivaldi antennas, which should provide operation in the frequency range allocated for fifth generation networks - 24.25-24.65 GHz. To determine the main parameters of the antenna, we applied modeling, on the basis of which we determined the main characteristics of the MIMO antenna array: the envelope correlation coefficient, the diversity gain, the multiplexing efficiency. According to the results, we determined that with a distance between antennas of 6.13 mm, the maximum possible characteristics of a MIMO antenna array are achieved, and a distance of 2.45 mm is sufficient for stable operation. The article gives the dimensions of the antenna under study, graphs of return loss (S11 - parameters), radiation patterns, envelope correlation coefficient, diversity gain, multiplexing efficiency at different distances between the antenna elements. Ensuring the stability of the MIMO antenna array is an important task since all modern communication systems use this technology to implement multichannel transmission, and, consequently, to increase the information transfer rate. We used specialized software to determine geometric characteristics and perform modeling
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Fouad, Sara, Reda Ghoname, Abd Elmonem Elmahdy, and Abd Elhalim Zekry. "Enhancing Tumor Detection in IR-UWB Breast Cancer System." International Scholarly Research Notices 2017 (March 19, 2017): 1–10. http://dx.doi.org/10.1155/2017/4606580.
Повний текст джерелаАнотація:
An ultra-wideband (UWB) microwave system for breast cancer detection is presented. The proposed system includes monocycle pulse generator, antipodal Vivaldi antenna, breast model, and calibration algorithm for tumor detection. Firstly, our pulse generator employs transmission gate in glitch generator to achieve several advantages such as low power consumption and low ringing level. Secondly, the antipodal Vivaldi antenna is designed assuming FR4 dielectric substrate material, and developed antenna element (80×80 mm2) features a −10 dB return loss and bandwidth ranges from 2.3 GHz to more than 11 GHz. Thirdly, the phantom breast can be modeled as a layer of skin, fat, and then tumor is inserted in this layer. Finally, subtract and add algorithm (SAD) is used as a calibration algorithm in tumor detection system. The proposed system suggested that horizontal antenna position with 90° between transmitting and receiving antennas is localized as a suitable antenna position with different rotating location and a 0.5 cm near to phantom. The mean advantages of this localization and tracking position around breast is a high received power signal approximately around mv as a higher recognized signal in tumor detection. Using our proposed system we can detect tumor in 5 mm diameter.
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Golovkov, Alexander A., Polina V. Terenteva, Alexander G. Zhuravlev, Michail S. Shmyrin, and Nikolay S. Stenyukov. "BROADBAND MICROWAVE VIVALDI ANTENNA USING COPLANAR FEED LINE." Journal of the Russian Universities. Radioelectronics, no. 6 (January 18, 2019): 13–19. http://dx.doi.org/10.32603/1993-8985-2018-21-6-13-19.
Повний текст джерелаАнотація:
Nowadays Vivaldi antennas are used as directional emitters with matching and balancing device at the input. As a rule, these devices cause additional losses in case of broadband operation. Besides, the use of the device leads to radiator pattern distortions, especially when operating in a wide frequency range. Stringent operating requirements (wide operating temperature, high humidity, salt fog, vibration, etc.), make the choice of proper chip very complicated. The aim of the study is to develop a slot antenna with a 50-ohm port at the input, which would be easy to manufacture and operate, while maintaining high gain in a wide frequency range. As is known, the field structure in the coplanar line is close to the field structure in the slit field close to it. As is known, the field structure in the coplanar line is similar to the field structure in the slot line. Using mathematics for such fields, means of electrodynamic modeling and numerical calculation, a system is developed that consists of two Vivaldi antennas fed by one coplanar line. Thus, the emitter has a close to a circular pattern and low losses in the structure of feeding, matching and balancing, the functions of which are performed by the coplanar line. The results are given for the frequency range of 1-6 GHz. The device as a whole is a dielectric substrate with radiating structure made as double-sided metallization. Finline-based emitters are acceptable to use for operation in higher frequencies. Antenna has low manufacturing cost and it is easy to repeat. Currently the authors are continuing work on the study of the use of such elements as part of antenna arrays.
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Honari, Mohammad Mahdi, Mohammad Saeid Ghaffarian, and Rashid Mirzavand. "Miniaturized Antipodal Vivaldi Antenna with Improved Bandwidth Using Exponential Strip Arms." Electronics 10, no. 1 (January 4, 2021): 83. http://dx.doi.org/10.3390/electronics10010083.
Повний текст джерелаАнотація:
In this paper, a miniaturized ultra-wideband antipodal tapered slot antenna with exponential strip arms is presented. Two exponential arms with designed equations are optimized to reduce the lower edge cut-off frequency of the impedance bandwidth from 1480 MHz to 720 MHz, resulting in antenna miniaturization by 51%. This approach also improves antenna bandwidth without compromising the radiation characteristics. The dimension of the proposed antenna structure including the feeding line and transition is 158 × 125 × 1 mm3. The results show that a peak gain more than 1 dBi is achieved all over the impedance bandwidth (0.72–17 GHz), which is an improvement to what have been reported for antipodal tapered slot and Vivaldi antennas with similar size.
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Korovin, K., and S. Kuzmin. "Implementation of UAV Communication Channel Using Airborne Wide-Band Low-Element Antenna Arrays." Proceedings of Telecommunication Universities 6, no. 2 (2020): 39–44. http://dx.doi.org/10.31854/1813-324x-2020-6-2-39-44.
Повний текст джерелаАнотація:
In this paper, we consider the the possibility of constructing a long-range communication link using a broadband low-element cylindrical antenna array based on Vivaldi antennas in 10 GHz band. A comparative analysis of the choice of emitters, optimization of the system according to the ratio of the number of elements and gain, and the assessment of overall characteristics are carried out. It is shown that the use of low-element cylindrical array allows one to obtain a compact antenna system with a gain of 13–16 dB, which allows one to construct a long-range communication channel.
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Jeon, Gwang-Hun, Philip Ayiku Dzagbletey, and Jae-Young Chung. "A Cross-Joint Vivaldi Antenna Pair for Dual-Pol and Broadband Testing Capabilities." Journal of Electromagnetic Engineering and Science 21, no. 3 (July 31, 2021): 201–9. http://dx.doi.org/10.26866/jees.2021.3.r.27.
Повний текст джерелаАнотація:
The non-standalone 5G antenna wireless communication standard and devices operating under Wi-Fi 5, 6, and 6E operate at the 3 GHz frequency bands and above. With the increasing demand for these devices and technologies, it is crucial to test them rapidly and economically for commercial usage. This paper presents a dual-polarized Vivaldi antenna for the over-the-air (OTA) measurement of wireless communication devices used in the 3–7 GHz band. The dual-polarization performance is realized by vertically intersecting two planar Vivaldi antennas and soldering them at the back end. A three-step 1/4 wavelength balun is applied to the input for the wideband impedance matching of the antenna, which is attached to a Teflon holder for easy mounting. It has excellent performance and is designed to be manufactured at low cost. The fabricated antenna was tested in an anechoic chamber and showed S11 less than -10 dB from 2.63–7.15 GH, and a realized gain of more than 5 dBi from 3 GHz and above. A measured half-power beam width of more than 60° was realized with symmetric E/H-plane. Much of the required symmetry was achieved with the designed Teflon holder. The antenna has a measured cross-polarization discrimination of better than 15 dB across the entire operating bandwidth.
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Dvorsky, Marek, Harihara S. Ganesh, and S. Sadhish Prabhu. "Design and Validation of an Antipodal Vivaldi Antenna with Additional Slots." International Journal of Antennas and Propagation 2019 (May 2, 2019): 1–10. http://dx.doi.org/10.1155/2019/7472186.
Повний текст джерелаАнотація:
This paper introduces an improved shape of Antipodal Vivaldi Antenna from the normal schematic structure which yields a high radiation gain. We have designed and fabricated the improved structure of Antipodal Vivaldi Antenna with the help of new dielectric substrate ASTRA®MT77 material. We have chosen a unique substrate material to develop our novel Antipodal Vivaldi Antenna because most research has been done on commonly used materials like FR4, RT Duroid, etc. Moreover, ISOLA has significantly good electrical and nonelectrical properties as compared with other substrate materials. The results of the desired antenna were simulated through extensive simulations performed in CST Microwave Studio®. The characteristics of all the antenna parameters are clearly studied and we are successful to achieve closed results between designed as well as experimented Vivaldi Antenna. The simulated antenna achieved a maximum gain of more than 9 dBi whereas the experimental antenna reached around 7 dBi between the operating frequency range from 1 GHz to 13 GHz. The measured prototype antenna provides linear polarization with overall radiation efficiency of more than 90%.
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Song, Lizhong, and Huiyuan Zhou. "Wideband dual-polarized Vivaldi antenna with improved balun feed." International Journal of Microwave and Wireless Technologies 11, no. 1 (August 1, 2018): 41–52. http://dx.doi.org/10.1017/s1759078718001113.
Повний текст джерелаАнотація:
AbstractThe paper researches a kind of wideband dual-polarized Vivaldi antenna with improved balun feed which consists of slot line and two bent coplanar strip lines. The whole of antenna structure is composed of two orthogonal Vivaldi antenna elements, and the mode of feeding adopts electromagnetic coupling from micro-strip line to slot line. The improved balun can avoid the intersection of transmission lines, reduce the size, and simplify the assembly. The electromagnetic simulation and optimization design of proposed antenna are carried out by using electromagnetic simulation software, CST. Simulation results show that the isolation between two polarized ports is more than 15 dB within working frequency range of 2–3.5 GHz and VSWRs of two ports are lower than 2.5 at the range of 2–3.5 GHz. The designed antenna is fabricated and measured. The measured results indicate that the designed antenna achieves anticipated patterns and feasible design of the dual-polarized Vivaldi antenna. The dual-polarized Vivaldi antenna with improved balun feed is suitable for some application fields, such as passive electronic reconnaissance, passive radar, and wideband communication and detection.
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Alshamaileh, K. A., M. J. Almalkawi, and V. K. Devabhaktuni. "Dual Band-Notched Microstrip-Fed Vivaldi Antenna Utilizing Compact EBG Structures." International Journal of Antennas and Propagation 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/439832.
Повний текст джерелаАнотація:
We propose an ultra-wideband (UWB) antipodal Vivaldi antenna (AVA) with high-Qstopband characteristics based on compact electromagnetic bandgap (EBG) structures. First, an AVA is designed and optimized to operate over an UWB spectrum. Then, two pairs of EBG cells are introduced along the antenna feed line to suppress the frequency components at 3.6–3.9 and 5.6–5.8 GHz (i.e., WiMAX and ISM bands, resp.). Simulated and measured results show a voltage standing wave ratio (VSWR) below 2 for the entire 3.1–10.6 GHz band with high attenuation at the two selected subbands. This simple yet effective approach eliminates the need to deform the antenna radiators with slots/parasitic elements or comprise multilayer substrates. Furthermore, the flexibility it offers in terms of controlling both the number and locations of the band-reject frequencies is advantageous for antennas with nonuniform flares as in the AVA.
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Mukminin, Moch Khafid, and Nurhayati Nurhayati. "LITERATURE STUDY OF HARVESTING ENERGY WITH RESOURCES RADIO FREQUENCY." INAJEEE Indonesian Journal of Electrical and Eletronics Engineering 3, no. 2 (August 28, 2020): 48. http://dx.doi.org/10.26740/inajeee.v3n2.p48-55.
Повний текст джерелаАнотація:
Energy harvesting is the process of harvesting energy from external sources such as solar energy, heat, wind and electromagnetic waves / radio frequencies. dimension. Research on harvesting energy needs to be developed because the use of non-renewable energy is increasingly limited. The use of radio frequency (RF) as a source of energy for harvesting is an effort to create environmentally friendly energy. This is due to the growing use of telecommunications technology. Various studies have been conducted by harvesting RF from various telecommunication signals and broadcasting media (AM / FM, TV / DTV, GSM signals, Wi-Fi signals). The purpose of writing this article is to study literature on the use of harvesting energy, especially those originating from radio / RF frequencies. A simple harvesting energy harvesting system consists of an antenna and a voltage rectifier circuit. The antennas used for RF energy harvesting have different designs according to the type of signal captured, including using periodic log antennas, archimedean spiral antennas, patch antennas, dipole patch antennas and vivaldi antennas. The energy yield obtained from the energy harvesting process with radio frequency sources tends to be small in the milliwatt scale (1.17 µW / cm2 - 20VDC) depending on the type of antenna and radio frequency used (0.3 - 27.5 GHz) and can be applied to low power electronic devices.
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Sobrinho, Raimundo Eider Figueredo, Alexandre Maniçoba De-Oliveira, Antonio Mendes De oliveira Neto, Alexandre Jean Rene Serres, Auzuir R. De-Alexandria, João Francisco Justo Filho, Marcelo B. Perotoni, Nurhayati Nurhayati, and Ingrid C. Nogueira. "Vivaldi Antipodal Antenna with High Gain and Reduced Side Lobe Level Using Slot Edge with New Neogothic Fractal by Cantor with Application in Medical Images for Tumor Detection." INAJEEE Indonesian Journal of Electrical and Eletronics Engineering 3, no. 1 (February 26, 2020): 25. http://dx.doi.org/10.26740/inajeee.v3n1.p25-31.
Повний текст джерелаАнотація:
This article addresses the study of the Vivaldi Antipodal Antenna (AVA) seeking to improve the gain, decrease the Side Lobe Level (SLL) and the squint, to make the antenna more directive and obtain a more stable radiation pattern. Its intended application lies in the generation of biological microwave imaging to detect brain tumors. With this objective, the Fractal Slot Edge (FSE) technique was applied with a new fractal developed and based on the Cantor set. The application of this fractal, called Cantor Neogothic Fractal (CNG), formed different-sized cavities resulting, in this work, in three antennas that were analyzed through numerical computational simulation together with AVA. The antennas, called CNG9-FSE-AVA, CNG18-FSE-AVA, and CNG27-FSE-AVA, in which 9, 18, and 27 define the maximum height that the fractal reached in each antenna, have areas equal to 354.66 mm2 , 709.33 mm2 and 1064 mm2 , respectively. All antennas achieved the goal, however, CNG27-FSE-AVA presented the best results at 2 GHz, with a gain of 7.84 dBi, SLL -19.80 dB, and squint of -0.10 degree. Additionally, it was proved that the antenna is suitable to generate a near field microwave imaging of tumors in a brain model.
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Dai, Li Hui, Chong Tan, and Yong Jin Zhou. "Ultrawideband Low-Profile and Miniaturized Spoof Plasmonic Vivaldi Antenna for Base Station." Applied Sciences 10, no. 7 (April 2, 2020): 2429. http://dx.doi.org/10.3390/app10072429.
Повний текст джерелаАнотація:
Stable radiation pattern, high gain, and miniaturization are necessary for the ultra-wideband antennas in the 2G/3G/4G/5G base station applications. Here, an ultrawideband and miniaturized spoof plasmonic antipodal Vivaldi antenna (AVA) is proposed, which is composed of the AVA and the loaded periodic grooves. The designed operating frequency band is from 1.8 GHz to 6 GHz, and the average gain is 7.24 dBi. Furthermore, the measured results show that the radiation patterns of the plasmonic AVA are stable. The measured results are in good agreement with the simulation results.
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Hamid, Mohamad R., Peter Gardner, Peter S. Hall, and Farid Ghanem. "Reconfigurable Vivaldi antenna." Microwave and Optical Technology Letters 52, no. 4 (February 11, 2010): 785–87. http://dx.doi.org/10.1002/mop.25030.
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Hamid, M. R., P. Gardner, P. S. Hall, and F. Ghanem. "Multimode Vivaldi antenna." Electronics Letters 46, no. 21 (2010): 1424. http://dx.doi.org/10.1049/el.2010.2092.
Повний текст джерела
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Suo, Ying, Wei Li, and Jianzhong Chen. "A SIW Antipodal Vivaldi Array Antenna Design." International Journal of Antennas and Propagation 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/9280234.
Повний текст джерелаАнотація:
A kind of compact SIW (substrate integrated waveguide) Vivaldi array antenna is proposed and analyzed. The antenna consisted of 4 Vivaldi structure radiation elements fed by an equal power divider with SIW technology. The radiation element is composed of antipodal index gradient microstrip lines on both sides of the substrate. The measured reflection coefficient of the array antenna is less than −10 dB from 8.88 GHz to 10.02 GHz. The measured gain of the array antenna is 13.3 dB on 9.5 GHz.
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Yahyaoui, Ali, Jawad Yousaf, Amira Dhiflaoui, Majid Nour, Mohamed Zarouan, Mohammed Aseeri, and Hatem Rmili. "Design and Comparative Analysis of Ultra-wideband and High Directive Antennas for THz Applications." Applied Computational Electromagnetics Society 36, no. 3 (April 20, 2021): 308–19. http://dx.doi.org/10.47037/2020.aces.j.360311.
Повний текст джерелаАнотація:
This work presents a comprehensive detailed comparative study of the three ultra-wideband and high directive antennas for the THz imaging, spectroscopy, and communication applications. Three different types of photoconductive antennas (log-spiral, Vivaldi, and bowtie antennas) are designed and simulated in the frequency range of 1 to 6 THz in the CST microwave studio (MWS). The enhanced directivity of the designed PCAs is achieved with the integration of the hemispherical silicon-based lens with the PCA gold electrode and quartz substrate of the proposed antennas. The performance of the designed PCAs is compared in terms of impedance and axial ratio bandwidths, directivity, and radiation efficiency of the proposed antennas. The reported log spiral, Vivaldi PCAs with added silicon lens exhibit the -10 dB impedance bandwidth of 6 THz, 3dB AR bandwidth of 5 THz, 6 THz, and 6 THz and peak total radiation efficiencies of 45%, 65%, and 95% respectively.
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Akhter, Zubair, Pankaj Kumar, and M. Jaleel Akhtar. "Sub-Surface Microwave Imaging Using Four-Slot Vivaldi Antenna with Improved Directivity." Frequenz 71, no. 1-2 (January 1, 2017): 19–28. http://dx.doi.org/10.1515/freq-2016-0054.
Повний текст джерелаАнотація:
Abstract The conventional tapered slot Vivaldi antenna is well known for its ultra-wide band characteristics with low directivity. To improve the directivity of the conventional Vivaldi antenna, a four-slot Vivaldi antenna (FSVA) is proposed here to operate in the frequency range of 2–11 GHz. For feeding the FSVA, a binomial three-section V-shaped even mode power divider with progressing T-junctions is also designed and tested here, which is then integrated with the antenna. The proposed antenna prototype is designed and fabricated on a 1-mm thick FR-4 substrate (ɛr=4.3, tanδ=0.025), and the return loss and radiation characteristics are investigated in the anechoic environment. The measured result shows a good agreement with the numerical simulation performed using the EM Simulator i. e. CST MWS-2015. It is found that the directivity of FSVA is approximately doubled as compared to that of the conventional Vivaldi antenna having the same dimensions. From the application point of view, the fabricated antenna is used to image various metallic objects hidden inside the sand using a vector network analyzer and associated RF components. The obtained 2D microwave images of the test media successfully show that the hidden objects can effectively be located and detected using the proposed FSVA in conjunction with a simple imaging scheme.
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Rittiplang, Artit, and Pattarapong Phasukkit. "1-Tx/5-Rx Through-Wall UWB Switched-Antenna-Array Radar for Detecting Stationary Humans." Sensors 20, no. 23 (November 29, 2020): 6828. http://dx.doi.org/10.3390/s20236828.
Повний текст джерелаАнотація:
This research proposes a through-wall S-band ultra-wideband (UWB) switched-antenna-array radar scheme for detection of stationary human subjects from respiration. The proposed antenna-array radar consists of one transmitting (Tx) and five receiving antennas (Rx). The Tx and Rx antennas are of Vivaldi type with high antenna gain (10 dBi) and narrow-angle directivity. The S-band frequency (2–4 GHz) is capable of penetrating non-metal solid objects and detecting human respiration behind a solid wall. Under the proposed radar scheme, the reflected signals are algorithmically preprocessed and filtered to remove unwanted signals, and 3D signal array is converted into 2D array using statistical variance. The images are reconstructed using back-projection algorithm prior to Sinc-filtered refinement. To validate the detection performance of the through-wall UWB radar scheme, simulations are carried out and experiments performed with single and multiple real stationary human subjects and a mannequin behind the concrete wall. Although the proposed method is an odd concept, the interest of this paper is applying the 1-Tx/5-Rx UWB switched-antenna array radar with the proposed method that is capable of distinguishing between the human subjects and the mannequin behind the concrete wall.