Compensating Quadrature Hybrid Mismatch Effects in Integrated Balanced Power Amplifier

This paper presents techniques to mitigate frequency dependent amplitude response of quadrature hybrid in an integrated quadrature balanced power amplifier (PA). The studied structure consists of stacked pseudo-differential power amplifiers and transformer-based quadrature hybrids designed with 22 nm CMOS FDSOI operating at 26 GHz. We propose two techniques to compensate frequency-dependent amplitude response of the quadrature hybrid when operating away from the center frequency. First one involves dual input drive and second asymmetric biasing. Measurements with continuous wave (CW) and high dynamic range fifth generation (5G) modulated signals demonstrate that the described techniques improve output power that can be reached within the linearity specifications when operating away from the center frequency.