Efficient analysis of a U-slot patch antenna using contour integral method with complex images

This paper attempts to analyze a general shaped patch antenna excited using either a probe feed or microstrip feed. The technique used is a combination of the 2-D contour integral method and the 3-D complex image method. This technique has been successfully applied for microstrip fed patch antennas (without slot) of arbitrary shape (Omar et al. 1995). The method used is highly convergent because it performs only a 2-D discretization of the contour (peripheral) of the patch and not a 3-D discretization of the patch itself. It is also accurate because it includes the effect of the fringe field at the edges of the patch through the 3-D complex images. The method is also versatile in the sense that it can solve arbitrarily shaped patch antennas with any slot shape. The contour integral method with complex images in Omar et al. is extended here to include the effect of a U-slot etched on the surface of the patch. The performance of the antenna with different patch shapes, slot sizes, locations and orientations is investigated.