High power 3-bit GaN high-pass/low-pass phase shifter for X-band applications

Purpose - The design and performance of X-band high power 3-bit phase shifter which has been fabricated in 0.25 mu m GaN HEMT technology are presented. Design/methodology/approach - Each bit of this phase shifter design is based on high-pass/low-pass topology. Findings - For all eight states, the insertion loss is 12.5 +/- 6 2.5 dB from 8-10 GHz and the input return loss is better than 9 dB over 8-10 GHz. The 3-bit phase shifter achieves a RMS phase error of 1o at 8.5 GHz and a RMS amplitude error less than 1.1dB. The measured continuous wave power data demonstrates typical input RF power handing capability of 32 dBm at 8 GHz. Originality/value - This is to the authors' knowledge the first published results of 3-bit AlGaN/GaN phase shifter.