High gain microstrip antenna element and array on low and high permittivity substrate

A new combination of aperture coupled microstrip antenna and a quasi-planar penetrating substrate PVC horn is demonstrated to increase the gain of the patch antenna by 6 dB - 8.68 dB for the patch on substrate having /spl epsiv//sub r/=2.2-13. We also report a new compact 4-element linear aperture coupled microstrip antenna array with surface mounted horn-frame to achieve 3.5 dB gain enhancement. The horn frame is made of plastic sheet and painted with silver epoxy.