mm-Wave Power Amplifiers with Wideband Efficiency, Ultra-Compactness and Built-in Sensors

A perennial challenge in power amplifier (PA) designs is to provide wideband efficiency (peak and backoff) and compactness at the same time to enable next-generation wireless communication and sensing applications. In this talk, we will first introduce a new class of wideband PAs using coupler balun output networks. The properties and design tradeoffs of wideband coupler balun PA output networks will be reviewed. We will then show that coupler baluns can be utilized to build both parallel and series wideband Doherty PAs that cover a nearly 3:1 bandwidth. A comparison between the coupler-based Doherty PAs and the Load Modulated Balanced Amplifiers (LMBAs) will be presented as well. Next, we will showcase our recent ultra-compact mm-wave Doherty PA design for high-density wideband multi-standard communication and SATCOM arrays. This mm-wave Doherty PA is built on an asymmetric 3-coil transformer, occupies a chip area smaller than a class-AB PA, and achieves record high backoff efficiency enhancement. Finally, we will compare the performance of Class-AB PA and Doherty PA over antenna load variation. To enable array large-signal built-in-self-testing (BiST), we will present on-chip VSWR-resilient complex impedance sensor and wideband true-power detector for unknown mismatched active antenna impedance in array operations.