Analysis on simple feed microstrip patch array antenna design for circular polarization diversity and beam switching with DOA estimation.

Abstract

The terminal node antenna of a wireless communication device should possess

the ability to perform many roles since modern communication necessitates the

adoption of advanced approaches to address the rapidly evolving needs of end

users. Circular polarization diversity, beam switching, and direction-of-arrival

estimation (DOA) are advanced antenna applications that can enhance power efficiency

and enable lossless transmission, therefore addressing the demands of the

present time. In addition, it is necessary for the devices, especially the antennas,

to have lower dimensions, even when considering long-distance communication,

which typically requires a large-scale array antenna. Integrating microstrip patch

antennas, which have a low profile and are lightweight, into transmitting or receiving

devices can resolve the problem. This thesis study focuses on the design

and simulation of a microstrip patch array antenna. The purpose is to analyze

its applicability in the areas of circular polarization, beam-switching, and DOA

estimation. A microstrip patch array antenna is constructed using both-sided

microwave integrated circuit (MIC) technology to achieve circular polarization

while keeping the feed network simple. A four-element microstrip patch array

antenna is constructed, simulated, and validated to determine the feasibility of

creating a large extensible array with 256 elements. The antenna utilizes a simple

single feed to achieve circular polarization. By making a simple adjustment

to the feed line, the formation of a Magic-T junction enables beam switching.

Additionally, a simple modification in the design allows for direction of arrival

(DOA) estimation. The simulation results demonstrate that the antennas have

the capacity to transmit across long distances with circular polarization, achieving

a gain of more than 26.15 dBic. Additionally, the antennas can alter their

beam direction by up to ±17◦. Additionally, they have the capability to determine

position by isolating the sum signal and the difference signal by different

ports.

Keywords: Array antenna, Beam switching, Both-sided MIC, Circular polarization,

DOA estimation, Left-hand circular polarization (LHCP), Magic-T, Microstrip

patch, Right-hand circular polarization (RHCP).