An Integrable Analog Domain Linearization Architecture for the Power Amplifiers in MIMO Systems

This study introduces a delay-compensated analog linearization framework to address nonlinear distortion in multi-input multi-output (MIMO) power amplifiers (PAs). The core design integrates a nonlinear distortion extraction loop and a tunable cascaded stage spectral notching structure. By dynamically adjusting the group delay and attenuation coefficients, the proposed framework achieves frequency-selective suppression performance of intermodulation distortion (IMD), particularly in dynamic beamforming scenarios. Experimental validation on a GaN PA (CMPA006002F) demonstrates a 6 dB improvement in adjacent channel power leakage ratio (ACLR) at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$780 \mathbf{~ M H z}$</tex> with a three ns feedback latency, outperforming prior single-branch architectures in suppression bandwidth.