Miniaturized D-Band SPDT/DPDT Switches Using Series Triple Coupled Transformer Cores in 65-nm CMOS SOI

This paper presents a novel SPDT/DPDT switch topology using a series triple coupled transformer (STCT) core, suitable for miniaturized millimeter-wave and terahertz systems. By controlling the ports' impedances of the six-ports STCT core, the high-order band-pass/band-stop response is realized, featuring low transmission loss or high isolation between ports. Additionally, the core occupies a highly compact area, making it suitable for the design of 1×2/2×2 switches and switch matrices. Fabricated in a 65nm CMOS SOI process, D-band SPDT/DPDT switches using the STCT core achieve a minimum insertion loss of 2.4 dB and 4.0 dB, with isolation greater than 19 dB and 31 dB from 110 GHz to 148 GHz. The core area of SPDT/DPDT switches is only 0.0028 mm² and 0.0058 mm², respectively.