Design of highly-efficient monolithic silicon power amplifiers using envelope-tracking for broadband wireless applications

A couple of design examples on highly-efficient fully-monolithic silicon-based envelope-tracking power amplifiers (ET-PA) for broadband wireless applications will be presented. These RF PAs are designed in SiGe BiCMOS technologies in either common-emitter (CE) or cascode topologies, as SiGe can deliver higher POUT with better breakdown robustness than their CMOS counterparts. The envelope modulator (EM) ICs are designed in CMOS to mate with PAs to form high-efficient monolithic SiGe BiCMOS ET-PA systems. Using 5/10/20 MHz LTE 16-QAM modulated inputs, these ET-PA systems can achieve 24–28 dBm linear POUT, passing stringent LTE linearity specs with overall system power-added-efficiency (PAE) above 40% without predistortion.