Branch-line couplers using unequal line lengths

Toker C., Saglam M., Ozme M., Gunalp N.

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, vol.49, no.4, pp.718-721, 2001 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 4
  • Publication Date: 2001
  • Doi Number: 10.1109/22.915448
  • Journal Name: IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.718-721
  • Keywords: branch-line couplers, hybrids
  • Middle East Technical University Affiliated: Yes

Abstract

General solutions for branch-line couplers using different Line lengths are provided in this paper. Explicit expressions are derived with which a hybrid with any given power division ratio can be designed. In the design, one of the characteristic impedances or lengths of the branches can be chosen arbitrarily to suit a given design specification, This approach brings flexibility in choosing the characteristic impedances or the lengths of the branches, and is helpful especially in monolithic-microwave integrated-circuit applications where restrictions imposed on microstrip transmission lines do not allow the use of conventional branch-line couplers employing quarter-wave-long lines, However, the resultant bandwidth is narrower compared to that of the conventional coupler.