Modified aperture coupled microstrip antenna

This work proposes a class of cavity-backed aperture coupled microstrip antennas and relevant design procedures. In the proposed structure, the radiating patch and the microstrip feed line are both fabricated on the top of a substrate, a coupling slot is etched on the bottom of the substrate, and a back-cavity is employed to block back radiation from the slot. The proposed antenna structures have potential for the implementation of lower profile and compact antenna size. Simulations and measurements show that the proposed antennas can operate at multiple frequencies with very good the ratio of front-back radiation and very low cross-polarized radiation.