Wideband Microstrip Patch Antennas and their Modifications for Practical Applications

Abstract

Printed antennas play an significant role in satellite, mobile, and other wireless communications networks, military systems and several more emerging applications in- cluding radar sensing and imaging. Several of these new applications not only have special demands for antenna designs but also require incorporation of smart features into it. In addition, research for high gain, wideband and compact antennas for several emerging technologies like 5G and IoT are rapidly progressing. In this work, design and analysis of several variants of wideband microstrip patch antennas are taken up. We begin with the design of a single layer suspended antenna where a small coplanar capacitive strip is used as the feed. Following a recent research from the group, di erent radiating patch shapes like rectangular, triangular and semi- elliptical patch geometries are compared with each other for various performance parameters. It is important that these wideband antennas must be able to transmit and receive short time pulses without any distortion and dispersion. Thus, parameters like group delay(GD) and fidelity factor(FF) are studied along with other parameters like re ection loss (S11), gain, polarisation, e ciency and radiation pattern. Full wave electromagnetic simulations using CST microwave studio is used to analyze these antenna characteristics. Triangular and semi-elliptical patches are fed in two di erent configurations (edge-feed and vertex-feed). Simulation studies showed that among the five configurations the vertex fed triangular antenna has the best performance in terms of at gain and low group delay variation over the frequency band of operation. Fabricated antenna has a return loss bandwidth from 3.1 GHz to 4.2 GHz at S11 better than -10 dB where the group delay variation is less than 2 ns. This antenna has a peak gain of 7 dBi and a beamwidth of 60 in both principal planes at the center frequency. Pulse propagation characteristics of this antenna is also studied using modulated sinusoid waveforms as the transm...