Frequency-Tunable narrow-band ladder-shape microstrip patch antenna for tv applications

Abstract

In this paper, a frequency-Tunable antenna is proposed based on a previous antenna which has a ladder shape and a size of 120 x 50 mm2. It is fed using a coaxial cable and it is operational at 700 MHz which is in the UHF band with a bandwidth of 30 MHz. Varactors, having a very low resistance value and a wide range of capacitance values, are implemented on the surface of the antenna which achieves tunability in the DTV applications band used for mobile handheld devices. By using such varactors, the electromagnetic characteristics of this antenna could be changed by changing its electrical length. Multiple cases are studied; either adding a varactor on each step of the ladder antenna or adding only one varactor in a certain well justified position. The operating frequency is swept in different ranges where all of the obtained frequencies could be used for digital TV broadcasting on mobile devices. © 2019 ASTES Publishers. All rights reserved.