A DESIGN METHOD FOR PATCH ANTENNAS WITH WIDE FREQUENCY TUNABLE RANGE AND STABLE CONICAL RADIATION

摘要

A design for patch antennas with a wide-frequency tuning range is presented. The antenna structure is composed of a top-loaded monopole and a parasitic shorted ring patch. With a variable capacitor and a microstrip exponentially tapered line, the operating frequency of the antenna can be tuned between two parallel resonant modes, both of which have symmetrical conical radiations. The key parameters of the proposed design are investigated for obtaining a maximum tuning range. A design procedure is also given. The results obtained demonstrate that the proposed antenna design can offer a frequency tuning range of more than 50%, and its radiation is stable within the range.