Slot‐loaded gap‐coupled microstrip array antenna for wide impedance bandwidth

Abstract

0.02 mm. The simulated and measured result of frequency response and phase response are shown in Figures 10 and 11, respectively. Good agreement is also observed between the simulated and the measurement results. The measured results of the miniaturized coupler are summarized in the Table 1. CONCLUSIONSAn extremely compact dual-band branch-line coupler operating in 0.9 GHz and 2.4 GHz is presented in this study. The size of this miniaturized coupler is reduced by 74% of the circuit dimension compared with the origin design with good circuit performance. Response of the miniaturized dual-band branch-line coupler and its equivalent circuit are in good agreement, and optimizing circuit performance using the circuit model could be implemented. Furthermore, the design is without lumped elements, via-holes, bound wires, and can be easily fabricated by using standard PCB etching processes, making this dual-band coupler suitable for MIC and MMIC applications. pedance bandwidth of microstrip antennas [1][2][3]. Among all the techniques, the aperture coupled feeding technique is simple and more effective as it has the freedom in designing the required feed line to energize the elements in enhancing the impedance bandwidth. Since in the aperture coupling the microstrip line feed and the antenna elements are separated by a ground plane, the effect of the feed line radiation on the antenna radiation characteristics is less, which improves the quality of antenna radiation pattern [4]. Further use of parasitic element in the form of gap-coupled to the radiating elements and use of slots will also effective in enhancing the impedance bandwidth. This concept has been utilized in designing the four-element gap-coupled slot rectangular microstrip array antenna (FGSRMSA). The obtained experimental results are discussed and presented in this letter. DESIGN AND EXPERIMENTAL DETAILSIn the present study, the antennas are fabricated on low cost glass epoxy substrate material of thickness h ϭ 1.66 mm and permittivity r ϭ 4.2. The geometry of conventional corporate fed four-element gap-coupled rectangular microstrip array antenna (FGRMSA) is as shown in Figure 1. The antenna geometry consists of radiating elements of length L R and width W R . A common parasitic element of length L P and width W P is placed between the radiating elements along their widths, which forms the gap coupling. The distance between the parasitic and radiating elements S is optimized and is taken as 0.025 g , where g is the operating wavelength in cm. The spacing between two radiating elements D R is kept at a distance of 1.5 0 /2. Usually in the array configuration the spacing between the two radiating elements is kept at a distance of 0 /2 for minimum side lobes [5]. But in this case, it is difficult to accommodate corporate feed arrangement between the two radiating elements when distance is 0 /2. If this distance is increased, accordingly the feed line has to be extended, which may increase radiation losses in the feed line. Hence, corporate feed arrangement...

Design and development of aperture‐coupled microstrip antennas for intensified bandwidth, adequate gain and low cross‐polarization

“…The field of applications of these antennas is limited by one of their principle limitations, that is, narrow bandwidth. Several techniques are disposed in the literature for intensifying the bandwidth of MSAs [1][2][3][4]. However, among all, the aperture-coupled technique is the simplest one.…”

“…By using a common laser input into the proposed nonlinear device system, the extended wavelength with power amplification can be achieved. However, many earlier visible laser investigations have been reported [1][2][3][4][5], which is capable ranging from visible to near-infrared region [6]. Recently, the use of a tiny device known as a microring resonator in various application has been reported [7,8], where the interesting results of light pulse propagating within a nonlinear microring device, where the transfer function of the output at resonant condition is derived and studied.…”

Wide bandwidth, high‐gain slot‐loaded rectangular microstrip antennas

“…The suppression of spurious signals can be achieved by parallel-coupled microstrip filters with overcoupled end stages [2]. The sinusoidal rule is used to eliminate spurious harmonics by continuously perturbing the width of the coupled lines in the microstrip wiggly-line filter [3]. In addition, with the stepped-impedance-resonators for planar microstrip bandpass filters [4,5], the second harmonic can shift to a higher frequency band and a wide stopband will appear.…”

“…But, one of the main limitations is their narrow bandwidth [1]. Several promising techniques are available in the literature for enhancing bandwidth of MSAs such as use of parasitic element [2], array technique [3], slot loading and stacked technique [4], gap-coupled technique [5], impedance matching technique [6] etc. Among the various techniques, the slot loading technique is simple and has freedom to the designer to add required slot on the patch, which also does not change the actual size of the patch.…”

Broadband, high gain slot loaded square microstrip array antenna

“…Patch array antennas can provide much higher gain and bandwidth than a single patch element but additional care should be taken for matching and feed arrangement. Many techniques such as aperture coupling [2], slot loading [3], gap coupling [4], etc. are available in the literature for enhancing the bandwidth and gain of MSAs.…”