Multisection impedance-transforming coupled-line baluns

Author

Sen Ang, Kian ; Leong, Yoke Choy ; Chee How Lee

Author_Institution

DSO Nat. Labs., Singapore

Volume

51

Issue

2

fYear

2003

Firstpage

536

Lastpage

541

Abstract

A new class of multisection impedance-transforming coupled-line baluns is presented in this paper. It is based on the quarter-wavelength coupled-line balun. By cascading several coupled and uncoupled-line sections, broad-band baluns with good amplitude and phase balance can be realized using simple microstrip coupled lines. The resulting circuit has a simple structure with minimal discontinuities that is highly suited for very high-frequency applications. Simple design equations and experimental verifications will be presented. Using microstrip coupled sections with even-mode impedance of 159 Ω, the fabricated balun achieved 0.5-dB amplitude balance over 30% bandwidth. With higher even-mode impedance, almost perfect amplitude balance was achieved over 100% bandwidth.

Keywords

baluns; electric impedance; microstrip components; microstrip couplers; microstrip discontinuities; network synthesis; 159 ohm; amplitude balance; balun bandwidth; broad-band baluns; cascading; coupled-line sections; design equations; design verifications; even-mode impedance; high-frequency applications; impedance transformation; microstrip coupled lines; minimal discontinuities; multisection impedance-transforming coupled-line baluns; phase balance; quarter-wavelength coupled-line balun; uncoupled-line sections; Application specific integrated circuits; Bandwidth; Coupling circuits; Equations; Frequency; Impedance matching; MMICs; Microstrip; Microwave integrated circuits; Monolithic integrated circuits;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2002.807813

Filename

1179424