A Comparative Study of Conventional Transition Model and Reverse Transition Model for Wireless and Radar Applications

Abstract

Microstrip line-to-waveguide transitions (MLWT) finds various applications in the field of RADAR engineering, navigation science, medical electronics, household equipment, satellite tracking equipment, wireless communications etc. Conventionally, the MLWT is designed so that the microstrip line is inserted in E-plane and perpendicular to the waveguide’s side wall, while the microstrip probe’s radiating face is towards the waveguide’s open end port. In this paper, an MLWT has been designed for Ka-band applications and the transition has been designed in such a way that the radiating face of the inserted microstrip line probe is towards the short circuit end of the waveguide. The method is called the reverse transition method. The microstrip signal reflected from the short circuit end comes in additive phase with the traveling wave and the strength of the traveling wave increases. MLWT has been developed using this method and results for Ka-band applications are presented in this paper. This work reported more than 20 dB improvement in return loss (RL), 0.1dB improvement in insertion loss (IL) and almost 7 to 8% enhancement in 10dB fractional bandwidth compared to the conventional method. Comparative analysis of the two methods has been shown in tabular form at the end of the paper.