A 32-to-38GHz Variable-Gain Phase Shifter with Impedance-Invariant Vector Modulation Achieving RMS Phase/Amplitude Errors of 0.33○/0.10dB in PS mode and 0.23○/0.08dB in VGA mode

As millimeter-wave (mm-wave) 5G technology advances, enhancing directivity and beam accuracy emerges as key technical challenges. This underscores the imperative for the development of high-resolution and high-precision phase shifters (PS) and variable gain amplifier (VGA) [1]. Impedance-Invariant VGA design based on MOS arrays are widely used due to their exceptional accuracy [2]–[3]. Nonetheless, designing PS and VGA separately escalates power consumption, heat radiation, and complexity of the phase array. An integrated approach to the variable-gain phase shifter (VGPS) utilizing the dual-vector synthesizing technique addresses concerns related to output impedance accuracy [4]. However, the VGA's input impedance still experiences fluctuations across different bias currents level. This inconsistency exerts a pronounced influence on the in-phase/quadrature signal generator (IQGen) due to the VGA's varied input impedances, causing high phase and amplitude errors.