Design of a Compact Dual-Band Absorptive Single-Pole Double-Throw Switch
Yo‐Shen Lin, Liwen Deng
Abstract
In this letter, a compact dual-band absorptive single-pole double-throw (SPDT) switch design is proposed. It utilizes the bridged-T coil as a miniaturized dual-band <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda /4$ </tex-math></inline-formula> transformer such that the concurrent dual-band operation in the on-state and the desired absorptive property in the off-state can be both achieved. The proposed design concept is validated through a 2.45/5.8-GHz dual-band absorptive SPDT switch design implemented in a commercial GaAs pHEMT process. The measured on-state insertion loss is 1.54/1.97 dB and the off-state isolation is 35/29 dB at 2.45/5.8 GHz, while the measured return losses at all ports are better than 20 dB at 2.45/5.8 GHz. In addition, a compact chip size of 2.0 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 1.5 mm is achieved.