Analysis of an Aperture-Coupled Microstrip Patch Antenna having and Asymmetric Cross Slot

Aperture-Coupled Microstrip Patch Antennas (ACMPAs) have plenty of advantages like no spurious radiation from the feed network, high radiation efficiency, and performance optimization of the feed part and the radiation part independently by choosing the different permittivities and thicknesses of the corresponding substrates [1]. For these reasons, many practical and theoretical studies have been performed to design and analyze ACMPAs [2][3]. To obtain dual-frequency operation, ACMPA with a cross slot could be used [4] and it is possible to provide more degrees of freedom in antenna design for dual-frequency characteristics than the ACMPA having an inclined slot [5]. In this paper, we suggested the analysis and the modeling of an ACMPA having an asymmetric cross slot for dual-frequency operation using improved transmission line model [2] based on the reciprocity theorem [6] and the spectral domain immittance approach [7]. With this modeling, we can achieve the easy way to predict the input impedance of the antenna and faster simulation time with good accuracy when compared with measurement results.