A 22-30 GHz Ultra Low RMS Phase Error SiGe HBT BiCMOS Active Vector Modulator Phase Shifter with a Tunable Two-Section Lumped Element Differential Quadrature Hybrid

This work presents a 5-bit Ka-band active vector modulator phase shifter (AVMPS) with ultra-low root-meansquare (RMS) phase error and low RMS gain error for emerging LEO SATCOM. To attain wideband operation, a tunable two-section lumped-element differential quadrature hybrid (TTQH) is proposed, with PIN diodes as tuning elements. By varying the PIN diode capacitance, the excellent I/Q signal amplitude balance can be obtained while keeping <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$89.0 \pm 1.2^{\circ}$</tex> phase difference from 22 to 30 GHz. Implemented in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.13-\mu \mathrm{m}$</tex> SiGe HBT BiCMOS, the proposed AVMPS covers a full 360° phase shift with an 11.25° resolution, and its measured RMS gain/phase errors are less than 0.65 dB/1.7° across 22-30 GHz, without any calibration.