Antipodal Vivaldi Antenna Array Research Articles

Design of antipodal vivaldi antenna with patch and corrugations for 5G applications

A compact 1 × 4 antipodal Vivaldi antenna (AVA) array designed for 5 G applications is introduced in this study. An elliptical-shaped parasitic patch and corrugation are strategically employed to enhance gain and bandwidth, making it well-suited for 5 G applications. The resulting AVA array with corrugation and parasitic patch (AVA-PC) is designed and simulated on ANSYS HFSS, demonstrating a stable gain ranging from 10 dBi to 11.7 dBi over the frequency range of 23.45 GHz to 28.74 GHz. The antenna, with 25.8 mm x 22.4 mm x 0.5 mm dimensions, is implemented on Roger's RT/Duroid substrate 5880.•Design uses an antipodal Vivaldi antenna to build a 1 × 4 AVA.•The array employs corrugations and an elliptical patch as a performance enhancement technique.•Simulated results confirm the designed antenna's practical utility for 5 G applications in a band of 23.45 GHz to 28.74 GHz.

Antipodal vivaldi array MIMO antenna for 5G FR2 applications at 28 GHz with improved isolation

Abstract This paper proposed a two port antipodal vivaldi antenna (AVA) for 5G FR2 (frequency range 2) applications at 28 GHz with improved bandwidth,gain and isolation. Each antenna consists of two array elements. The proposed antenna has dimensions 23.8 × 54 × 0.79 mm3 and is fabricated on Rogers RT/Duroid 5880 material. This material has a 2.2 low dielectric constant and mainly suitable for broadband high frequency applications. Proposed antenna covers −10 dB below from 25.51 to 33 GHz band, which having 7.49 GHz bandwidth. Gain for the presented MIMO (Multiple input multiple output) AVA array is varying from 8.50 to 12.44 dBi. A better isolation −34.56 dB is obtained between two antenna elements. MIMO characteristics like ECC (Envelope correlation coefficient), CCL (Channel capacity loss), DG (Diversity Gain), TARC (Total active reflection coefficient), and MEG (Mean effective gain) are satisfied with good results for presented antenna. The proposed antenna is designed using ansys HFSS simulation tool.

A novel structure based on ultra-wideband filtering circuit for isolation enhancement of Vivaldi antenna with narrow gap in H-plane

A novel structure based on ultra-wideband (UWB) filtering circuit for isolation enhancement of Vivaldi antenna with narrow gap in H-plane is proposed in this paper. An antipodal Vivaldi antenna array with series of parallel slots in feed arms and a reflective floor is adopted to gain lower profile height, higher front-to-back ratio (FBR), and better isolation in high frequencies compared to a conventional one. The proposed filtering decoupling structure (FDS), composed of three bow ties with slender serrated lines at the edges distributed on both sides of the dielectric plate, is not only located in the necessary path of the spatial coupling of the two units, but also electrically connected with the reflective floor to enhance the low-frequency decoupling effect. The measured results show that the decoupling antenna array works well in 1.8–12 GHz, and the isolation is improved by 24.1 dB at 3.2 GHz and 12.2 dB at 1.9 GHz with FDS. The proposed FDS works well from 1.6 to 4.7 GHz with bandwidth of 96.7%, and the minimum isolation in the operating frequency band is improved from 10 dB to 19 dB. Moreover, the radiation performance remains superior after decoupling. The proposed decoupling structure is potential in the application in large-scale UWB arrays.

A corrugated and lens based miniaturized antipodal Vivaldi antenna for 28 GHz and 38 GHz bands applications

Abstract The paper presents a dualband and compact antipodal Vivaldi antenna (AVA) array by using a dielectric lens (DL) and corrugations for 5G applications. The proposed novel antenna provides very high efficiency and it alleviates beam titling very effectively. Its efficiency is in the range of 95.93%–97.52% whereas the H plane beam titling is ± 1 ° $\pm 1{}^{\circ}$ over most of the frequency range. The antenna frequency response is improved by incorporating corrugations which results in the antenna miniaturization. The designed AVA array size is 2.86 × 3.58 × 0.06 λ g 3 ${{\lambda }_{g}}^{3}$ (for lower guided frequency). The proposed dualband antenna operates from 24.17 GHz to 29.37 GHz and 30.76 GHz to 40.58 GHz. These frequency bands cover 28 GHz and 38 GHz bands of 5G communications. Next, the front-to-back ratio is improved significantly which further results in the gain enhancement. Also, the grooves in the feeding network minimize reverse power reflections. The radiation pattern is stable and it shows that the designed antenna is a directional antenna. The antenna is designed, simulated, and tested by using a network analyzer and anechoic chamber. The testing and simulated results indicate that the proposed AVA array is the best candidate to integrate it in 5G devices.

Antipodal Vivaldi Antenna with enhanced gain and improved radiation patterns for 5G-IoT applications using metamaterial and Substrate Integrated Waveguide

An analysis of a novel antipodal Vivaldi antenna (AVA) with constant high gain and enhanced radiation patterns is presented in this paper. The antenna consists of a 1 × 4 AVA array, fed by substrate integrated waveguide (SIW). Next, the corrugations are added to the AVA array with SIW (AVAS) to increase the gain up to 1.5 dBi. Further gain enhancement and radiation pattern improvement are achieved by incorporating square-shaped split-ring resonator (SRR) metamaterial at the aperture of the AVAS array with corrugations (AVAS-C). The designed AVAS-C array with metamaterial (AVAS-CM) provides an enhanced gain of 16.2 ± 0.8 dBi over the 37.9 GHz to 45 GHz frequency range. Also, the proposed AVAS-CM array gives stable radiation patterns. Its front-to-back ratio (FBR) is above 21.3 dB, the sidelobe level (SLL) is below −13.6 dB, and E-plane beam titling is ±1∘. In compact devices, an antenna with low FBR and SLLs is essential to avoid radiations in the wanted directions to alleviate the degradation of electronic components. This paper presents the first time use of the SIW technique for improving the radiation pattern characteristics of the AVA array. Experimental and simulated results show that it is suitable for compact 5G-IoT devices.

Performance enhancement of antipodal Vivaldi antenna array using metamaterial for 38 GHz band of 5G applications

A compact 1 x 4 antipodal Vivaldi antenna (AVA) array with enhanced gain and front to back ratio (FBR) for 38 GHz band of 5G applications is presented in this paper. The FBR is improved by incorporating slanting rectangular corrugations in the AVA flares. The proposed antenna provides a peak FBR of 23.55 dB at 38.8 GHz. The gain of the AVA array with corrugations (AVA-C) is further improved by adding split-ring resonator (SRR) shaped metamaterial unit cells (MUCs) at the aperture of an antenna. The gain of the proposed AVA-C array with metamaterial (AVA-CM) is 7.4 dBi to 12.84 dBi over 36.53 GHz to above 43.5 GHz. The AVA-CM array is designed, simulated, fabricated, and verified its results using a vector network analyzer and anechoic chamber. Both the experimental and simulated results prove that the proposed AVA-CM array is an appropriate choice to integrate into devices for the 38 GHz band of 5G applications.

Design of a high-gain dual-band antipodal Vivaldi antenna array for 5G communications

AbstractThis paper presents a dual-band 1 × 4 antipodal Vivaldi antenna (AVA) array with high gain to operate over a dual-frequency band that covers the 5G frequency spectrum. The gain is enhanced by employing a dielectric lens (DL). The AVA array consists of four radiating patch elements, corrugations, DL, and array feeding network on the top side. The bottom side contains four radiating patches which are the mirror images of top radiating patches. The designed AVA contains 1 × 4 array antenna elements with a DL that is operating in the ranges of 24.59–24.98 and 27.06–29 GHz. The dimensions of the designed antenna are 97.2 mm × 71.2 mm × 0.8 mm. For the improvement in gain and impedance matching at the dual-band frequency, corrugation and feeding network techniques are used. The gain obtained is about 8–12 dBi. AVA array is tested after fabrication and the measured results are reliable with the simulation results.

An antipodal Vivaldi antenna array based on spoof surface plasmon polariton metamaterial with 5G mm Wave suppression

An efficient method for achieving an antipodal Vivaldi antenna array with filtering performance based on spoof surface plasmon polariton (SSPP) metamaterial is proposed. The array is fed by a 1-to-8 power divider integrated with SSPP structures—named SSPP-I. The loaded SSPP-I obtains high cutoff frequency at 24 GHz. Both numerical simulations and measurements suggest the proposed array has a good performance in the desired frequency band from 22.01 to 24 GHz, in which the measured radiation patterns show a high gain level of 9.83 dBi on average, and the highest and lowest values are within 0.27 dBi of the average. The filtering performance, flat gain, low cost, and low profile have wide applications in the development of mmWave radio astronomy systems and can suppress the interference of 5 G mmWave to the system.

A compact wide-bandwidth Antipodal Vivaldi Antenna array with suppressed mutual coupling for 5G mm-wave applications

A modified miniaturized Antipodal Vivaldi Antenna (AVA) array with suppressed mutual coupling is proposed for broadband 5G millimeter wave (mm-wave) application. The configuration is constructed by using eight radiating elements with single 1-to-8 power divider networks. By adding several notch structures, printed on the ground plane, the mutual coupling between the array elements are suppressed. Therefore, the radiating system has maximal additional isolation of 35.6 dB, enhanced gain of 13.36 dB, and extended impedance bandwidth of 26.5–29.5 GHz. In order to validate the design of the radiating system, the AVA array configuration is fabricated and measured with an overall dimension of 21.45 × 52.35 × 0.787 mm3. The experimentally validated gain value of the conventional AVA array antenna and modified array antenna is 4.7–8.35 dB and 8.62–12.67, respectively.

Ultra‐wideband fluidically steered antipodal Vivaldi antenna array

AbstractAn ultra‐wideband 1 × 4 antipodal Vivaldi antenna array with microfluidic beam steering is reported. The antipodal configuration is selected for its microstrip feed line, which is convenient for implementation of the phase‐shifting structure. Each antenna element uses a true‐time‐delay phase shifter consisting of nine microfluidic channels under its feed line in which deionized (DI) water, ɛ r = 77 + j13 (tanδ = 0.17) at 3 GHz, is pumped to change the speed of the propagating wave. The array was fabricated using a 1.52 mm thick substrate with ɛ r = 3.55 and tanδ = 0.0027. Each antenna element and phase shifter measures 55 mm × 140 mm. Measurements show that the array yields up to 90° of beam steering from 3 to 6.5 GHz and up to 40° of steering from 6.5 to 10 GHz. The array has a maximum realized gain of 13.1 dBi, and a half‐power beamwidth of less than 40° for all configurations.

A Survey of Performance Enhancement Techniques of Antipodal Vivaldi Antenna

The increasing proliferation of advanced devices for UWB, 5G communication, micrometer-wave, and millimeter-wave communication demands an antenna which can handle huge data rates, provides high gain and stable radiation pattern as a panacea of most of the current wireless communication problems. Many different antenna designs have been proposed by the researchers but, Antipodal Vivaldi Antenna (AVA) has drawn the attention of most of the researchers because of its high gain, wide bandwidth, less radiation loss, and stable radiation pattern. Different methods are presented to make AVA more compact while maintaining the performance of an antenna to an acceptable level. These different methods are substrate choice, flare shape, slots, and feeding connectors. Also, AVA performance can be enhanced by incorporating corrugation, dielectric lens, patch in between two flares of AVA, balanced AVA (BAVA), metamaterial, computational intelligence (CI), and AVA array. The AVA performance enhancement techniques modify the electrical and physical properties of an antenna which in turn improves its performance. A large number of performance enhancement methods of AVA design have been proposed, however, no comprehensive study exists to categorize these performance enhancement techniques and outline their concepts, advantages, disadvantages, and applications. So, in this paper, we have attempted to outline all methods available for enhancing and optimizing the parameters of AVA. Additionally, to validate some of the important performance enhancement methods, they are incorporated in the basic conventional AVA design and further simulation results are obtained for the same which are in line with the surveyed literature. Each method is explained in detail by incorporating its key points, merits, and demerits. Moreover, illustrations from the literature are given to demonstrate improvement in the parameters as a result of applying a particular performance enhancement technique.

Vivaldi Antenna Array Using Defected Ground Structure for Edge Effect Restraint and Back Radiation Suppression

A compact printed planar antipodal Vivaldi antenna (AVA) array with high gain is presented. First, a novel method based on adding line-type defected ground structures (DGSs) between adjacent antenna elements is utilized to reduce the mutual coupling in the AVA array. It is accompanied by the reduced cutoff frequency and improved gain simultaneously. Second, inconsistent performance between edge and center elements can be decreased by adding a pair of semiring-shaped DGSs to the edges of the AVA array. Thus, the directivity of antenna array can be improved. Third, to reduce antenna array impact on back-end systems, multiple gradual semicircle-shaped DGSs are etched into the back end of the AVA array. The frequency band of the proposed AVA array is 24.37–28.5 GHz, and the gain is improved from 7.78–8.9 dB to 9.7–11.6 dB in the frequency band of 5G millimeter-wave communication when compared with the original AVA array. Finally, to verify the designed methods, the proposed AVA array was successfully fabricated and measured, and the measured results are in good agreement with the simulations.

Wideband high‐gain SIW‐fed antenna array for mm‐Wave applications

AbstractA wideband high‐gain mm‐Wave antenna array operating in Ka‐band is reported. The antenna element consists of an antipodal Vivaldi antenna (AVA) with plated through vias on the edges of the radiating arms, which is utilized to eliminate the harmful gap resonance due to the electrically discontinuity. A modified wideband 8‐way substrate integrated waveguide (SIW) power divider is proposed to feed the linear array. In addition, in order to enhance antenna gain, a stacked dielectric superstrate is employed, which achieves 2.3 dBi average gain improvement over 25‐40 GHz. The proposed structure provides superior bandwidth of 25.4‐40 GHz with S11 < −9.5 dB (corresponding to VSWR < 2). The modified SIW power divider, 1 × 8 AVA array and the dielectric superstrate are designed and fabricated, resulting in a wideband and high‐gain structure as compared to other SIW‐fed antennas. A prototype is experimentally verified. The measured results show that the impedance bandwidth ranges from 25.37 to 39.48 GHz (S11 < −9.6 dB, relative bandwidth of 43%). The measured gain varies from 15.5 to 18.5 dBi in the frequency range with an average gain of 16.6 dBi.

A 16‐modified antipodal Vivaldi antenna array for microwave‐based breast tumor imaging applications

AbstractIn this article, an improved method is introduced for enhancing the gain and directivity of a modified antipodal Vivaldi antenna, which is suitable for detecting malignant cells in the breast through microwave imaging. By slotting on the fins of the antenna with the addition of parasitic elliptical patch makes the antenna radiation more directive with more gain at the lower band range. The operating fractional bandwidth of this proposed Vivaldi antenna is 120% (2.50‐11 GHz) with compact dimension and directive radiation pattern with 7.20 dBi highest gain. The antenna time‐domain performance and the near‐field directivity (NFD) are also observed. Effective microwave breast phantom imaging system with an array of 16 antipodal antennas is designed where one antenna works as a transmitter and rest of the antenna works as a receiver in turn. The imaging performance is investigated with tumor inside the breast phantom using the Microwave Radar‐Based Imaging Toolbox open source software. Detection of tumor tissue inside breast phantom has been identified by analyzing the modified antipodal Vivaldi antennas' backscattered signal.

A New Method for Achieving Miniaturization and Gain Enhancement of Vivaldi Antenna Array Based on Anisotropic Metasurface

A low-profile printed planar antipodal Vivaldi antenna (AVA) array with good performance for future fifth-generation (5G) millimeter-wave (mmWave) communication applications is presented. The proposed structure is an $8\times1$ array with eight elements in E-plane, which is fed by a 1-to-8 power divider network. A novel feature called anisotropic metasurface (MS) is located at the aperture, resulting in low cutoff frequency reduced from 24.55 to 24.1 GHz for miniaturization. In addition, the phase distribution located at the aperture of AVA array can be corrected by adding MS. Thus, the gain of AVA array can be improved from 8.5–11.2 to 9.35–12 dB in the frequency band of 5G mmWave communication. Finally, to verify the designed methods, the proposed AVA with MS (AVA-MS) array was successfully fabricated and measured, which occupies an area of $6.11\lambda _{\mathrm {g}} \times 2.93\lambda _{\mathrm {g}} \times 0.08\lambda _{\mathrm {g}}$ . The numerical and experimental results coincide well with each other, which certify the new method for achieving miniaturization and gain enhancement of our proposed AVA-MS array.

A Compact Gain-Enhanced Vivaldi Antenna Array With Suppressed Mutual Coupling for 5G mmWave Application

In this letter, a novel method of reducing mutual coupling is proposed, and it used on a modified compact broadband antipodal Vivaldi antenna (AVA) array for future 5G millimeter-wave (mmWave) communication application. The proposed structure consists of eight antenna elements that are fed by a 1-to-8 power divider. In order to reduce the mutual coupling between AVA array elements, multiple notch structures are added on the ground plane. Thus, the isolation between the antenna elements can achieve a maximal additional 37.3 dB enhancement, impedance bandwidth is extended slightly from 24.65–28.5 GHz to 24.55–28.5 GHz, and the gain is improved simultaneously. To verify the designed method, the proposed AVA arrays were fabricated and measured. They show an overall size of 28.823 mm × 60 mm × 0.787 mm. The measured gain of the modified AVA array is 6.96–11.32 dB in the frequency band of future 5G mmWave communication, which is higher than the initial AVA array, whose gain is 5.34–8.5 dB.

A Miniaturized Gain-Enhanced Antipodal Vivaldi Antenna and Its Array for 5G Communication Applications

In this paper, a miniaturized gain-enhanced antipodal Vivaldi antenna (AVA) with gradual corrugated edges (GCEs) and triangular metal directors (MDs) is investigated. Its operating frequency band is extended and the gain is improved at lower frequencies due to the use of GCEs. In addition, the E-plane beam tilt has been removed and the improvements on side-lobe level are achieved. By applying triangular MDs on the two surfaces of the radiation aperture of the AVA, its gain at higher frequencies is improved. Therefore, the gain variation tends to be flat within the whole operating band. Furthermore, a compact $1 \times 8$ E-plane AVA array with a small size of $54.4 \times 28.2 \times 0.508$ mm3 is also designed, fabricated, and measured. A measured gain is 12.3–12.9 dB in the operating frequency band of 24.75–27.5 GHz, which covers the candidate band for the fifth generation (5G) communication. Good directivity, symmetrical radiation patterns, and compact structure make the proposed AVA array suitable for integration in devices for 5G communication applications.

A Wideband End-Fire Conformal Vivaldi Antenna Array Mounted on a Dielectric Cone

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.