Study On The Improvement Of Bandwidth Of A Rectangular Microstrip Patch Antenna

Abstract

Microstrip antennas or patch antennas are popular for their attractive features such as low profile, low weight, low cost, ease of fabrication and integration with RF devices. Micro strip antennas have been found favorable because they are inexpensive to manufacture and compatible with monolithic microwave integrated circuit designs (MMIC). They are usually employed at UHF and higher frequencies because the size of the antenna is directly tied to the wavelength at the resonance frequency. A Microstrip or patch antenna is a narrowband, wide-beam antenna fabricated by etching the antenna element pattern in metal trace bonded to an insulating dielectric substrate with a continuous metal layer bonded to the opposite side of the substrate which forms a ground plane. The most commonly employed microstrip antenna is a rectangular patch. The major disadvantages of Microstrip antennas are lower gain and very narrow bandwidth. Microstrip patch antennas have some drawbacks of low efficiency, narrow bandwidth (3-6%) of the central frequency. Millimeter wave technology being an emerging area is still much undeveloped. As micro strip antennas have found wide variety of application areas, a number of techniques are evolved to improve its limited bandwidth. A good approach to improve the bandwidth is increasing the thickness of substrate supporting the micro strip patch. However problems exist on the ability to effectively feed the patch on a thick substrate and the radiation efficiency can degrade with increasing substrate thickness. A substantial research needs to be done in this area as its applications are numerous. The radiation patterns and S11 performance are used for the analysis of the different configurations. In the present endeavor a rectangular patch antenna is designed on thick substrate and simulated using MATLAB software and configuration on different dielectric susbstrates was used .