Planar wideband crossover with distortionless response using dual-mode microstrip patch

A microwave crossover using a dual-mode microstrip patch is presented. The patch is designed to operate at two orthogonal modes. Each of those modes is used to couple a pair of face-to-face ports. The isolation between the two orthogonal modes is enhanced by using symmetrical slits in the microstrip patch. The proposed crossover has the main features of high-power handling capability and distortionless response due to its extremely low group delay deviation. A prototype is designed to operate at the WLAN band from 5.15 to 5.85 GHz. The simulated and measured results indicate less than 0.06 ns deviation in the group delay, less than 1 dB insertion loss, more than 13 dB return loss and more than 12 dB isolation across the whole band. (C) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2077-2079, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27028