22-30GHz Quadrature Hybrid SCPA with LO Leakage Self-Suppression and Distributed Parasitic-Cancelling Sub-PA Array for Linearity and Efficiency Enhancement

Abstract

To meet the demands of multi-Gb/s data-rate wireless transmission such as millimeter wave (mmW) 5G wireless, there is a growing requirement of mmW transmitters (TXs) with high output power, high efficiency, and high data-rate [1], [2]. The digital power amplifier (DPA) shows the merits of high system efficiency, high integration with baseband, and low cost compared with analog PAs [3], which is potential for mmW 5G TX. However, the increasing parasitic of transistor at mmW limits switching speed, which leads to efficiency degradation [4]–[6]. Meanwhile, the routing parasitics deteriorate the output power and efficiency of mmW DPA [5]. DPA usually suffers from relatively large LO leakage at mmW, which decreases the dynamic range and introduces linearity issue. To overcome these challenges, a 2×9-bit quadrature hybrid switched-capacitor PA (SCPA) with LO leakage self-suppression and distributed parasitic-cancelling sub-PA array is proposed, which achieves saturated Pout of 24.03dBm with peak system efficiency (SE) of 31.5% at 24GHz.