Digital Predistortion Implementation in Short-range mm-wave Six-port Transceivers

The paper proposes an innovative digital predistortion (DPD) technique for a direct conversion transceiver, utilizing a six-port network in the mm-wave frequency bands. The technique involves pre-distorting the baseband signal before modulating it to the carrier frequency in the transmitter, thereby improving the linearity of modulation and demodulation process. A feedback loop from the six-port demodulator in the receiver continuously monitors the output signal and compares it to the desired signal. The DPD unit has been implemented in a pre-designed mm-wave six-port front-end that was previously developed in our laboratory, and experimental results show significant improvements in signal quality by minimizing nonlinearity errors.