180-Degree Branch Line Coupler Composed of Two Types of Iris-Loaded Waveguides

Hidenori Yukawa, Yu Ushijima, Takeshi Yuasa, Naofumi Yoneda, Moriyasu Miyazaki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


We propose a 180-degree branch line coupler composed of two types of iris-loaded waveguides. The proposed coupler consists of two main transmission lines and branch lines with different electrical lengths. Optimal electrical lengths enable to achieve 180-degree output phase difference without additional phase shifters. The two main lines with different electrical lengths are realized by capacitive and inductive iris-loaded waveguides. We designed a proposed coupler in K-band. The size of the proposed coupler is almost same as the usual 90-degree branch line coupler. So the proposed coupler presents an advantage of compactness, in comparison with the conventional 180-degree coupler with additional phase shifters. The design results demonstrated a return loss of 22dB, an isolation of 25dB, a coupling response of 3dB+/-0.1dB, phase differences of 0deg+5/-1deg and 180deg+5/-1deg with a bandwidth of 8% in the K-band.

Original languageEnglish
Title of host publication2018 48th European Microwave Conference, EuMC 2018
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages4
ISBN (Electronic)9782874870514
Publication statusPublished - 2018 Nov 20
Externally publishedYes
Event48th European Microwave Conference, EuMC 2018 - Madrid, Spain
Duration: 2018 Sept 252018 Sept 27

Publication series

Name2018 48th European Microwave Conference, EuMC 2018


Other48th European Microwave Conference, EuMC 2018


  • branch line
  • coupler
  • iris-loaded
  • phase shifters
  • waveguide

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Instrumentation
  • Radiation


Dive into the research topics of '180-Degree Branch Line Coupler Composed of Two Types of Iris-Loaded Waveguides'. Together they form a unique fingerprint.

Cite this