A compact dual asymmetric L-slot frequency reconfigurable microstrip patch antenna

Abstract

A frequency reconfigurable microstrip patch antenna with two asymmetric L-slots is proposed in this article. Two RF pin diodes inserted on the asymmetric L-slots are used to switch the operating frequency over the C band. Design and optimization of different physical parameters of the antenna viz. slot dimensions, feed location, notch size, and pin diode positions are carried out using High Frequency Structure Simulator Version 13.0. The design is implemented on an FR4 substrate (εr =4.4) of dimension (35 × 40 × 1.6) mm3. DC bias circuitry for RF PIN diode activation is also integrated with the antenna. Switching combinations of two PIN diodes offer four reconfiguration modes of operation at 4.75, 5.05, 5.11, and 5.18 GHz. In all the states, the −10 dB bandwidth shows minimal changes with average variations of 15.8% with respect to the state when both PIN diodes are OFF. The gains of the antenna for different modes of operation are found almost stable with an average of 6.64 dBi.