Frequency agile microstrip rectangular patches using varactor diodes

A technique for controlling the operating frequency of microstrip rectangular antennas was investigated experimentally and theoretically. The method consists of placing varactor diodes at appropriate locations and then biasing the diodes. Measurements and theoretical calculation were performed for a 5.3-cm*4.5-cm edge-fed patch using Arlon LX with a thickness of 0.7874 mm and a relative dielectric constant of 2.17. BB 405B silicon UHF variable-capacitance varactor diodes were used as tuning devices. Good agreement between experimental results and theory was achieved.<<ETX>>