Ultra-wideband Antipodal Vivaldi Antenna Research Articles

A Compact Ultrawideband Antipodal Vivaldi Antenna and Its Efficacy in Through-Wall Imaging

A Compact Ultrawideband Antipodal Vivaldi Antenna and Its Efficacy in Through-Wall Imaging

Ultra-wide band antipodal Vivaldi antenna design using target detection algorithm for detection application

This work presents a technique for detecting targets between two walls using ultra-wide band (UWB) modified antipodal Vivaldi antenna (MAVA). The detection system works on principle of time domain reflectrometry (TDR) using through wall imaging (TWI). This technique utilized a vector network analyzer (VNA) to produced short and small pluses to irradiate through an antenna array system onto the wall under study. The purposed detection system operated in UWB frequency spectrum (3.1 GHz to 10.6 GHz). Furthermore, an algorithm for hidden target detection has been developed. The results of the simulation of the designed antenna revealed a significant level of penetration, demonstrating a smart advancement in detecting and imaging system, to locate hidden metallic targets with good accuracy. A signal processing technique have been employed to improve the resolution of the target image. Using computer simulation technology (CST) software, the development and optimization process of an antenna is carried out, and the parametric performance of return loss, directivity and radiation pattern is evaluated.

A UWB Antipodal Vivaldi antenna with high gain using metasurface and notches

This paper presents a planar ultra–wideband Antipodal Vivaldi Antenna (AVA) working over a super ultra–wideband frequency range of 1.5–55 GHz, found to suffice for various communication standards including that of the 5G mm-Wave communication, microwave imaging, non-destructive testing, defense applications, etc. The proposed antenna, fabricated on a single layer Rogers substrate (RO4003C) having a dielectric constant of 3.38, has a compact dimension of 96 mm × 175 mm × 0.508 mm, i.e., 0. 80 × 0.875 × 0.00254 λ03, where λ0 is the free space wavelength at the lowest frequency of operation. The designed antenna has exponential flaring and a tapered slot edge. Moreover, an elliptical parasitic patch is placed between the flares of the AVA to improve the directive gain. Dielectric lens and metasurface are used to further enhance the gain. The measured return loss, radiation pattern, and gain of the designed AVA are found to be in good agreement with the results obtained from the full-wave electromagnetic simulation.

Radar-based microwave breast cancer detection system with a high-performance ultrawide band antipodal Vivaldi antenna

In this study, a novel ultrawide band (UWB) antipodal Vivaldi antenna with three pairs of slots was designed to be used as a sensor in microwave imaging systems for breast cancer detection. The proposed antenna operates in UWB frequency range of 3.05-12.2 GHz. FR4 was used as a dielectric material and as a substrate for forming the antenna that has a compact size of 36 mm x 36 mm x 1.6 mm. Frequency and time domain performance of the proposed antenna have been investigated and results show that it meets the requirements for UWB radar applications with linear phase response, nearly constant group delay, ultrawide bandwidth, and directional properties at most of the operating frequency. Then, the capacity of the proposed antenna as a sensor was tested in a monostatic microwave breast imaging system that was developed in the CST Microwave Studio (CST MWS) simulation software. In the simulation application, 50 mm radius hemisphreical breast models with different densities were formed and 2 mm diameter spherical tumor was placed inside them. Antennas were positioned cylindrically around the breast to send Gaussian pulse and collect backscattered signals. After signal processing steps, tumors were screened at correct positions with high resolution. Finally, a monostatic radar-based breast phantom measurement system was developed to automatically scan the breast phantom in the prone position. To perform experimental measurements, an electrically and anatomically realistic homogeneous breast phantom with tumor inside was fabricated. Screening of the tumor at correct location indicates that the proposed antenna and the microwave imaging system developed using this antenna are suitable for the detection of breast cancer at the early stage.

UWB Antipodal Vivaldi antenna with higher radiation performances using metamaterials

In this paper, an Ultra-Wide-Band (UWB) Antipodal Vivaldi antenna with higher radiation performances is proposed. Zero-index metamaterials units with Meander-line shape are placed on the antenna aperture to improve the antenna directivity. An increase of 4 dB in the gain with equal beamwidths in the E and H planes is achieved at different frequencies. The antenna covers 142.8% bandwidth with input match better than − 10 dB from 1.3 GHz to 12 GHz. It has practically unchanged radiation patterns over the operating bandwidth where the gain varies from 9.5 dB at 5 GHz–12.4 dB at 10 GHz. Measurement results show satisfactory agreement with simulation. Therefore, loading with metamaterials makes the VIVALDI antenna directivity frequency independent. This UWB antenna is eventually a good candidate for wireless communications and radar applications.

Microwave and millimetre wave antipodal Vivaldi antenna with trapezoid‐shaped dielectric lens for imaging of construction materials

High-quality microwave and millimetre wave imaging of construction materials and structures requires ultra-wideband (UWB) techniques to provide high-range resolution as well as a reasonable penetration depth. A modified compact microwave and millimetre wave UWB antipodal Vivaldi antenna is designed and presented in this study. First, the conventional antipodal Vivaldi antenna is designed as a reference antenna. Then, to provide the desired frequency range (3.4-40 GHz) with increased gain at its lower frequencies, the slit edge technique is applied, thus creating a periodic slit edge antipodal Vivaldi antenna (PSEAVA). Finally, a trapezoid-shaped dielectric lens (TDL) as an extension of the substrate is added and optimised to increase gain and directivity at higher frequencies of the frequency range, creating PSEAVA with a TDL (PSEAVA-TDL). The results show that the PSEAVA-TDL has the highest gain (up to 16 dB) and front-to-back ratio (up to 37.5 dB), and the narrowest half power beamwidth (down to 11.7°). A prototype of the proposed PSEAVA-TDL with compact size of 40 × 90 × 0.508 mm 3 is fabricated and applied for the imaging of samples made of construction materials. High-range resolution images of the samples are obtained with this antenna by using synthetic aperture radar algorithm.