Broadband compact CPW-fed metasurface antenna for SAR-based portable imaging system

Abstract

A broadband and compact coplanar waveguide (CPW) coupled‐fed metasurface (MS)‐based antenna for C‐band synthetic aperture radar (SAR) imaging application is proposed in this article, which is consisted of 16 uniform periodic square patches performed as radiators. The CPW feeding structure gives two following functions: (1) It excites an aperture coupling slot structure underneath the center of MS patch array. (2) It acts as a ground plane for the metasurface patch units. Different slots were investigated and eventually an hourglass‐shaped slot is applied to enhance bandwidth for imaging applications. A prototype with a dimension of 60 × 60 × 1.524 mm3 (1.1λ0 × 1.1λ0 × 0.03λ0) operating at the center frequency 5.5 GHz (f0) has been fabricated and measured to verify the design principle. This antenna has a measured impedance bandwidth of 12.4% from 5.14 to 5.82 GHz, a peak gain of 9.2 dBi and averaged gain of 7.2 dBi at broadside radiation. Microwave imaging experiments using the proposed antenna have been carried out and a good performance is achieved.

Compact wideband tapered‐fed printed bow‐tie antenna with rectangular edge extension

“…According to the needs of these specific applications, performances of PBAs have been tried to be improved. There are many useful methodologies such as implementations of metamaterials, feeding line modifications, employment of slots, different ground plane variations, matching stubs and lumped elements, fractal and array structures, parasitic directors, reflectors and additional bow extensions are suggested in order to improve the performances of PBA in terms of radiation pattern, gain, and bandwidth. However, relatively smaller structures have comparably narrower bandwidths while the ones with relatively wider bandwidth have larger dimensions .…”

“…2 In the literature, there are many studies about PBAs for very wide range of specific applications such as ground penetrating radar, synthetic aperture radar (SAR) imaging, cancer detection, medical sensors, radio astronomy, wireless communication, direction finding, 5G communications, antenna measurements, UHF and digital video broadcasting (DVB) reception, GPS, RFID, millimeter wave, and pulse-based systems. [3][4][5][6][7][8][9] Singlesided and double-sided PBAs can be counted as two main types of them. Employment of coplanar waveguide (CPW) feeding is the most practical way to realize single-sided PBAs, 9,10 when parallel transmission and microstrip lines are frequently used in double-sided PBAs.…”

“…[3][4][5][6][7][8][9] Singlesided and double-sided PBAs can be counted as two main types of them. Employment of coplanar waveguide (CPW) feeding is the most practical way to realize single-sided PBAs, 9,10 when parallel transmission and microstrip lines are frequently used in double-sided PBAs. According to the needs of these specific applications, performances of PBAs have been tried to be improved.…”

Wideband beam-steerable configuration of metasurface loaded slot antenna

“…The wavefront of incident electromagnetic (EM) waves can be modulated using the metasurface (MS) structures . In the past, the metasurfaces (MSs) have been used for variety of applications like reduction in EM coupling of microstrip antenna array, SAR imaging, gain enhancement, and so on. It has also been used in a circularly polarized and a Fabry‐Perot cavity antenna .…”

Implementation of the inverse circular radon transform-based imaging approach for breast cancer screening

“…In RBMWI, a scattering map of the measured tissue is generated. There are various studies on TBMWI and RBMWI in the literature such as confocal MWI, statistical MWI, matching‐pursuit‐based imaging, dynamic MWI, MUSIC‐inspired imaging, asynchronous particle swarm optimization and dynamic differential evolution‐based imaging, circular, and indirect holographic imaging, delay and sum procedures and its various alternatives …”