A K/Ka-Band Low RMS Phase Error 5-Bit CMOS Phase Shifter

The paper presents a K/Ka-band low root mean square (RMS) 5-bit CMOS phase shifter. A biphase switching reflection-type based topology with wideband phase-shift performance is applied to the 90° phase-shift bit. The fabricated 5-bit CMOS phase shifter with an intrinsic digital phase-control mechanism, achieves a low RMS phase error and a low RMS amplitude error, less than 4° and 0.8 dB from 26 to 32 GHz, respectively. The lowest RMS phase error is 2° and amplitude error is 0.8 dB, at 29 GHz. The measured insertion loss is $16\pm 2\mathrm{d}\mathrm{B}$ from 26 to 32 GHz over all 32 states.