An active inverted patch antenna with wideband varactor-tuned capability

A varactor-tuned inverted circular patch antenna has been developed with a power variation of /spl plusmn/1.0 dB over a 13 percent tuning bandwidth. A simple equivalent circuit has been used to model the active antenna, and the calculated results agree well with the experimental results. The circuit should have many commercial applications in wireless communications, radar, and sensors.