Numerical Matrix Analysis for Performances of Wideband 100GHz Branch-Line Couplers

The wideband waveguide 3-dB branch-line coupler suitable for use in SSB heterodyne receivers in radio astronomy is designed and its performances are reported. The coupler is designed by a numerical analytical method by using matrices based on the circuit theory and has good performances in the range of frequencies from 84GHz to 116GHz.The numerical analytical method presented in this manuscript enables quick calculations for performances of RF components and possesses advantages over electromagnetic simulation software in common use.