A Millimeter-Wave Direct Digital Transmitter Using Multiphase Subharmonic Switching PA

Abstract

This article presents a direct digital transmitter (TX) employing a multiphase subharmonic switching (MP- SHS) power amplifier (PA) to achieve both high peak and power back-o ff (PBO) e fficiency with wide signal bandwidth. A phase-shifted subharmonic (SH) local oscillator (LO) divider is proposed to suppress SH spurs with minimal implementation overhead by introducing an additional phase shift during LO frequency division. Furthermore, a dual-rate hybrid digital- to-analog converter (HDAC) is integ