Vector Modulator Based Low RMS Phase Error Phase Shifter for Ka-Band Applications

This paper presents the design and development of a Vector Modulator type phase shifter operating in the Ka-band. This system is based on an I/Q hybrid transformer that feeds a vector modulator, which adjusts the amplitude of quadrature differential signals. A specially designed passive attenuator enhances attenuation depth, phase accuracy, and impedance matching. A 55nm CMOS circuit was simulated, achieving a 360° phase shift with 5.6° resolution and exhibiting an RMS phase error of less than 2°. The designed phase shifter occupies a total area of 0.22 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, and its reflection coefficient remains below −10 dB across different bias conditions It spans the frequency range from 25 to 27 GHz, paving the way for high data rate mobile millimeter-wave telecommunication systems