Considerations of branch-line couplers of power split ratio 2:1

摘要

A spurious-notch may occur by the design of a stub, in the branch-line coupler that materialized 1/4 miniaturization in comparison to area by compacting a transmission line by using two-step stubs. In this paper, it examines about spurious notch of the miniaturized branch-line coupler of power split ratio 2:1. Also, we propose a branch-line coupler that has a point that all S parameters agree in a higher frequency than a center frequency. On the circuit that compensated a discontinuous part and lose joint errors between 2 step stubs, the experimental results are reported.