Image-Rejection Up-/Down-Converter LO Distribution Chain for 5G mm-wave Phased-Array Systems

Abstract

This paper reports on a local-oscillator (LO) distribution chain suitable for 5G mm-wave image-rejection up-/down-converter. The chain consists of a single-ended-to-differential active converter, which achieves low phase and amplitude imbalance, minimizing the area occupation. Secondly, a frequency doubler is included in the frontend. Following, buffer amplifiers boost the second-harmonic amplitude extracted from the doubler, and a differential polyphase quadrature filter generates two I/Q couples of differential signals, such that four signals can feed two up- or down-converter mixers to achieve sideband suppression for up-conversion operations or image-rejection for down-conversion, respectively. The LO chain is suitable to be provided with an input signal ranging from 11.5 to 13.5 GHz and achieving outputs from 23 to 27 GHz with quadrature capabilities. Finally, the maximum single-ended saturated output power is −1 dBm at 26 GHz and stays above −3.2 dBm for the entire band.