Novel Corrugated Microstrip Patch Antenna: Effects on Resonant Frequency, Coupling and Cross Polarization

Microstrip patch antennas are very often used in array configurations where there might be specific requirements such as antenna gain, beamwidth and polarization. In this paper, a single patch antenna element is corrugated in different ways and depths as a novel design geometry. As a building block in an array, the proposed geometry is studied in detail to investigate its effects on the well-known drawbacks of a microsrtip patch antenna, i.e. the fringing effects and the parasitic coupling arising between array elements. It is found that patch corrugations strongly affect the resonant frequency, so that, if properly controlled, they might compensate the arising fringing effect and almost eliminate the undesired coupling between antenna elements. And surprisingly, the cross-polarization levels in the H-plane (unacceptably high for some applications) are greatly reduced and can be eliminated to some extent on the cost of a slight reduction of the gain. Full-wave analysis simulations with HFSS (finite element) and Sonnet (MoM) software are used in the investigations.