MoM Analysis of Narrow Wall Round End Slot Coupler

In this paper a computationally efficient Method of Moments (MoM) formulation for the analysis of round end slot coupled narrow wall Round end slot coupler is presented. The slot coupler has been analyzed for the three types of slots, namely the basic rectangular slot, rectangular slot with semicircular ends (Type 1) and rectangular slot with slightly curved ends (Type 2), and the performance characteristics are evaluated for each slot model. From the knowledge of the electric field coefficients at the two interfaces of the thick coupling slot, the reflection, transmission and coupling coefficients are determined. The insertion loss, return loss, VSWR and coupling have been evaluated for the case of a narrow wall longitudinal slot coupler using two similar WR-90 X-band rectangular waveguides. A comparison among the numerical results for round end slots of (Type 1 and Type 2), and the rectangular slots has been presented.