Reduced branch-line coupler using eight two-step stubs for W-Band application of MMIC

摘要

We have designed and fabricated a branch-line coupler to examine the possibilities of fabrication for various passive components, to apply millimeter waves using newly proposed transmission lines, i.e. DAMLs. In order to reduce the size of the branch-line coupler, we designed the reduced blanch-line coupler with DAML structure using eight two-step stubs. We see that the area of the blanch-line coupler with structure DAML was reduced by 40%. It was shown that the fabricated branch-line coupler has wideband characteristics of the coupling loss of 3.61 dB and transmission loss of 4.25 dB at a frequency of 100 GHz. Also the isolation characteristic and return loss were -35.5 dB and -36.9 dB at 100 GHz, respectively.