CPW-fed frequency-agile shorted patch

A shorted patch fed by a coplanar waveguide is der:eloped and compared to t he existing feed type. Its characteristics are presented in terms of impeda nce matching, frequency bandwidth, as well as radiation pattern. Simulation s and experimental results are exposed, and allow us to validate this feed, which facilitates the active component insertion. As an example of the ass ociation active devices, the patch is loaded by a varactor diode, making th e antenna frequency agile. (C) 2000 John Wiley & Sons, Inc.