https://file.scirp.org/pdf/Engineering20090100005_36820044.pdf

Microstrip Antennas Loaded with Shorting Post

This paper presents the design of a dual stacked microstrip antenna over the frequency range of 9.5–16 GHz. Investigations show that in the new structure the impedance bandwidth of the antenna is increased to 44% and the thickness of the antenna decreases to 0.14λ. Furthermore, the gain bandwidth of the antenna (above 8 dB) is increased to 5.1 GHz (40%).

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A high gain dual stacked aperture coupled microstrip antenna for wideband applications

Using gap coupling between the elements, an antenna of four sectors by cutting the slots through and through from a circular patch is designed for application in X-band. The bandwidth enhancement along with reduced sidelobes is obtained by marginally or fully moving one of the feeding sectoral patches diagonally away. The results are analyzed for different positions of the slot. A bandwidth of 1.2 GHz in X-band along with a reduced sidelobe level of -15.0 dB and a gain of 12.0 dBi is obtained. An analysis of mutual coupling and parasitic patch effect is also presented and discussed in this letter.

A Novel Design of Gap-Coupled Sectoral Patch Antenna

This paper presents an aperture coupled microstrip antenna with a rectangular patch which is located on top of two slots on the ground plane. The patch and slots are separated by an air gap and a material with low dielectric constant. There is a 50 Ω feed line which is divided into two 100 Ω feed lines by a two way microstrip power divider under the ground plane. Using a parametric study on the effect of the position and dimensions of the feed line the impedance bandwidth of the antenna (VSWR < 2) is increased to 7.9 GHz (86%) centered at 9.25 GHz and the gain of the structure is more than 7 dB from 5.4 GHz to 8.8 GHz (48%).

Slot coupled microstrip antenna for ultra wideband applications in c and x bands

In this paper the numerical computation of resonant frequency of gap coupled circular microstrip antennas using the concept of cavity model has been presented. The resonant frequency of the gap-coupled circular patches is computed and the mode number is also evaluated. The computed results are compared with published results. The previously published results are based on experimentation and do not present a clear mathematical model for the same structure. An extensive comparison with Method-of-moments based software (IE3D) is also done. The accuracy of prediction is reasonably good.

Numerical Computation of Resonant Frequency of Gap Coupled Circular Microstrip Antennas

Different methods to increase the bandwidth of a microstrip antenna, such as use of an air-gap in-between stacked resonators and the ground plane and planar multiresonators, are combined to achieve broad bandwidth with increased gain. A configuration with two gap-coupled circular microstrip antennas on the top dielectric layer stacked with one coaxial-fed circular patch on the bottom layer and an air-gap in-between two layers and the ground plane yield a bandwidth of 1093 MHz (47%) with a gain of 9.54 dB at the S-band frequency of 2.325 GHz. Also, dual-band response with broadside radiation and improved gain at both frequencies is achieved by suitably changing parameters of this configuration. Parametric studies of this configuration on dielectric substrate for both broadband and dual-band operation are presented in this paper. The experiments are performed on broadband and dual-band configurations, which are in agreement with the theoretical results. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 489–494, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21208

Multilayer multiresonator circular microstrip antennas for broadband and dual‐band operations

In this paper, new configurations with two gap-coupled triangular microstrip antennas and its compact version have been investigated at S band. The gap coupled configuration yields 2.38 times and compact gap coupled configuration gives 2.65 times BW as compared to that of a corresponding equilateral triangular microstrip antenna (ETMSA). The area reduction for the latter configuration is by factor of 2.05 as compared to an ETMSA

K. Nirmala

Papers

Multilayer multiresonator circular microstrip antennas for broadband and dual‐band operations

Compact Broadband Gap-Coupled Microstrip Antennas