A NOVEL MICROSTRIP PATCH ANTENNA WITH LARGE IMPEDANCE BANDWIDTH IN VHF/UHF RANGE

In this paper a novel antenna is presented. This antenna, employing microstrip circular disc as radiator is seen to perform over a large impedance bandwidth (130 MHz to 876 MHz). The disk resonator is loaded with L-C-R circuit across a selective location in the disk via a thin shorting pin. The theoretical modeling predicts TM01 mode of operation. Therefore the beam pattern shows a null in the broadside direction. The said antenna is proposed to be developed for end use in coal mine where the antenna can be flush mounted on coal strata. Thus it will be able to measure the angle of arrival of any reflective component due to presence of waterbed at a distance. The measured as well as simulated results regarding impedance bandwidth and beam pattern agrees well. The simulated efficiency using IE3D is 48% whereas measured efficiency is nearly 45%.