28-07-2011, 04:00 PM
[attachment=14871]
Abstract
This paper present the design of an S-band circular microstrip patch antenna using a conventional coaxial probe feed technique. The antenna is designed to function within the frequency range of 2.0 GHz - 2.5 GHz, S-band. The antenna exhibited a return loss of -16dB and a directivity of 6.07dB. The microstrip patch antenna is designed on FR4 epoxy substrate and is to be feed with a 50 coaxial cable. The design of the antenna is done using MATLAB software and SonnetLite software for the electromagnetic simulation. Index Terms-circular patch antenna, coaxial probe feed, S-band, substrate.
1 Introduction
Microstrip patch antennas have found extensive application especially in wireless communication systems owing to their advantages such as low profile, conformability, low cost fabrication and ease of integration with feed networks [1]. They have also received increasing interest since they can provide tremendous advantages over traditional whip and helix antenna in terms of high efficiency, low profile and increased mechanical reliability. At the same time, its flat profile and reduced weight, compared to parabolic reflectors and other antenna option, makes it attractive for airborne and spacecraft applications [2]. Circular patch antennas can be used either as antennas [3] or as components of oscillators and filters in microwave integrated circuit (MIC’s) since the bandwidth of microstrip patch resonator around their resonant frequencies is very narrow [4]. Circular microstrip antenna in its simplest form consists of a sandwich of two parallel conducting layers separated by a single thin dielectric substrate. The lower conductor function as a ground plane and the upper conductor is a simple circular patch [5] whose height is small (h << ), as a circular cavity. Recent research on circular patch antenna design can be found in [6], [7], [8] and [9]. In this paper, the design of a circular patch antenna in the S-band with potential satellite communication application is presented. The cavity model is used for the design of the circular patch because of its suitability over other models while the optimization of the patch radius and probe feed point were obtained using Sonnet. The result presented in this work is obtained from the simulation carried out on the designed antenna using both MATLAB and SonnetLite. Fabrication was made possible by interfacing MATLAB with Multisim Ultiboard for antenna printing prior to photolithographic etching.
