Circularly Polarized Stacked Patch Antenna With Perpendicular Feed Substrate

A circularly polarized stacked patch antenna with a perpendicular feed substrate is presented. The antenna uses a new type of transition to couple from the patch to the microstrip feed line, and is demonstrated to operate in a scanning linear array at 20 GHz. Coupling from the stacked patch to the perpendicular microstrip feed is through a slot in the ground plane of both the stacked patch and the perpendicular substrate. Performance of the antenna element has been optimized in an infinite linear array configuration. A finite array consisting of eight elements has also been analyzed for various scan angles, built and tested. Computed reflection coefficient, realized gain, axial ratio and radiation patterns are provided for the linear array element, and measured performance presented for an eight-element linear array prototype.