Designs of bandwidth-controllable impedance transformers using dual transmission lines

• DOI: 10.1049/el.2012.1541
• Publication Date: 2012-07-20T07:23:48Z
• Authors: Jui-Ching Cheng; Eric S. Li; Yu Jia Huang
• Keywords: Quarter-wave impedance transformer; Characteristic impedance

The technique of dual transmission lines is applied to replace quarter-wave transformers for impedance transformation. By varying the electrical lengths two lines, bandwidths proposed are reduced and become adjustable. Two designs presented illustrate these characteristics. rectangular configuration minimises coupling between its input/output ports; whereas ring allows ports be arranged in any desired directions. Simulation results indicate larger difference electric narrower bandwidth transformer. validity computed data verified by measuring examples prepared both designs. measurement close agreement with simulation results.