An X-Band Slow-Wave T/R Switch in 0.25-mu m SiGe BiCMOS

This brief presents a fully integrated X-band transmit/receive (T/R) switch using slow-wave transmission lines for X-band phased-array radar applications. The T/R switch was fabricated in a 0.25-mu m SiGe bipolar CMOS (BiCMOS) process and occupies 0.73-mm(2) chip area, excluding pads. The switch is based on shunt-shunt topology and employs isolated n-channel (NMOS) transistors and slow-wave microstrip lines. Additionally, resistive body floating and dc biasing are employed to improve the power-handling capability (P-1 (dB)) of the switch. The T/R switch resulted in a measured insertion loss of 2.1-2.9 dB and isolation of 39-42 dB from 8 to 12 GHz. The input referred P-1 dB is 27.6 dBm at 10 GHz. To our knowledge, this brief presents the utilization of slow-wave transmission lines in T/R switches for the first time. Furthermore, it can simultaneously satisfy stringent isolation, insertion loss, and power-handling capability requirements for implementing a fully integrated SiGe T/R module.