Analysis of two aperture-coupled cavity-backed antennas

The feasibility and performance of an aperture-coupled cavity-fed microstrip patch antenna and an aperture-coupled cavity antenna are demonstrated using reciprocity and moment method analyses, followed by practical design guidelines and equivalent circuit models. Each antenna incorporates a thick ground plane that can be useful as a heat sink for active MMIC circuitry and as structural support for thin substrates. Prototype antennas show good experimental agreement with the analyses in each case. The resonators of the aperture-coupled cavity-fed patch antenna are optimized to achieve a prototype having a measured 2:1 bandwidth of 26%. The size of the aperture-coupled cavity antenna can be easily reduced for array applications by filling the cavity with a dielectric material.