A wideband microstrip antenna with symmetric radiation patterns

Abstract

A wideband microstrip antenna using a coplanar capacitive feed with nearly 50% impedance bandwidth has been realized on a stacked air‐dielectric substrate with only one metal layer above the ground plane. In this article an approach of modifying the patch shape is proposed to obtain symmetric radiation patterns in the entire frequency band of this antenna. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1991–1995, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23575

Dual Band Coplanar Capacitive Coupled Microstrip Antennas With and Without Air Gap for Wireless Applications

“…It may be noted from Figures 8(a) and (b) that the shift in the resonant frequency in the second case is due to the use of different substrate (dielectric constant) and absence of air gap. However, it may be redesigned to any frequency of interest as suggested in [9][10][11][12][13][14][15]. All measured results fairly agree with the simulated values.…”

“…A long pin SMA connector is used to connect the feed strip which couples the energy to a radiating patch by capacitive means. The length and width of the patch are designed for 2 GHz operation as suggested in [9][10][11][12]. The radiator patch is loaded with a vertical slot to make the antenna resonant for lower frequencies and for proper matching with the input impedance of the antenna.…”

“…It may be recalled that, cutting a slot inside the radiator patch ensures the wide bandwidth [3]. The detailed parametric studies have been reported earlier for the optimization of this geometry [9][10][11]13] Experimental validations (with simulated characteristics) of the geometry are presented in Section 4.…”

“…Other parameters (t, d, and s) of capacitive feed have been optimized as suggested in [9][10][11][12]. It may be noted that initial values of these parameters have been taken from [13] for optimization.…”

“…It is well known that considerable bandwidth enhancement can be achieved by increasing the overall height of the composite airdielectric medium [9][10][11][12][13][14]. However, the use of air gap increases the height/volume of the antenna which is undesired in several (compact) applications [15].…”