Experimental Evaluation of A Dual-Band Microstrip Antenna with Tunable Frequency Characteristics Based on Varactor Diodes

This paper presents an experimental evaluation of a dual-band microstrip antenna which has tunable frequency characteristics. The tunable characteristics of the proposed antenna offer the advantage to tune the operating frequency at the desired one without altering geometry or dimensions of the antenna. To achieve a dual-band microstrip antenna with these characteristics, four varactor diodes are involved into the design to influence the resonant frequency of antenna. Prototype of the proposed microstrip antenna is then realized for experimental evaluation. The measurement results demonstrate that the prototype resonates within the frequency range of 0.83 GHz to 1.2 GHz when the DC voltage across the varactor diodes is increased from 0 V to 12 V.