A microstrip hybrid structure for the implementation of compact transition bandpass filters is proposed in this paper. Now-adays wireless communication systems have high data rate such as satellite communications, radar systems, shuttle imaging radar and other wireless communication systems operates in wide band frequencies. The proposed transition consists of two quarter wavelength microstrip patches and a half wavelength slot on common ground. The elliptical patches on the lower and upper substrates are coupled with the common ground. The slot/aperture coupled transition is basically a band pass circuit and is realized via electromagnetic coupling, and different slot shapes are investigated in order to enhance the bandwidth. This paper proposes an elliptical shaped microstrip, which provides better gain and less return loss and low VSWR value for high frequency bands. A sample transition is designed and measured in a frequency range of 2.8 to 8.5 Ghz at 10 dB return loss.
