A new type of GaN HEMT based high power high-pass/low-pass phase shifter at X band

This paper presents a new type of robust GaN HEMT-based high power phase shifter operating at X-band. The proposed 0°/45° high-pass/low-pass phase shifter exhibits low insertion loss (2.5 dB), good return loss, and amplitude variation lower than 0.5 dB for the two phase states over the entire operational bandwidth ranging from 6 to 13 GHz. The relative phase performance is fairly constant over the bandwidth. The proposed phase shifter MMIC has been successfully demonstrated using a 0.8 µm gate GaN HEMT process.