A K-Band Low-Loss High-Isolation CMOS SPDT Switch Based on Multi-Tap Inductor Technique

A K-band single-pole double-throw (SPDT) transmit/receive (T/R) switch is presented in this paper. To improve bandwidth while decreasing chip area, the switch is designed using multi-tap inductor together with capacitors that replaces the pi/4 transmission line. It achieves a measured minimum insertion loss of 1.62 dB at 21 GHz, with an isolation of 24 dB. Measured output port to port isolation is better than 22 dB. The return losses at all ports are better than 10 dB from 14 to 28 GHz with a P-1dB of 8 dBm. It is fabricated in 65 nm CMOS and occupies a core chip area of 0.035 mm(2).