An aperture coupled stacked patch antenna with 50% bandwidth

Microstrip patches are an attractive type of antenna due to their low-cost, low-profile, conformability, and ease of manufacture. The aperture coupled configuration also provides the advantage of isolating spurious feed radiation by use of a common ground plane. The primary barrier to implementing these antennas in many applications, however, is their limited bandwidth-only of the order of a few percent for a typical patch radiator. A technique is presented which extends the operating bandwidth (defined as having a return loss of less than -10 dB) of the aperture coupled microstrip antenna to over 50%. Design considerations for the antenna are discussed, and geometrical aspects of an experimental design are given. Theoretical and measured results for the experimental design are presented and compared.