This article demonstrates a frequency-tunable dual-band branch line coupler based on composite right/left-handed transmission lines. A simple, yet effective conversion enables to design such transmission lines in a form that can be frequency tuned. A tuning function is realized with varactors. For demonstration, a dual-band branch line coupler at 0.6 and 1.2 GHz is fabricated. Tuning ranges of 51.4 and 18.0% are measured in the lower and upper band, respectively, in which/S21/S31/ < ± 0.5 dB is obtained, when maintaining S11 below -10 dB.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering