A 3W 55% PAE CMOS PA with Closed-Loop 20:1 VSWR Protection

A 0.25 μm 2V CMOS PA for GSM applications delivers 3W output power with 55% PAE. A closed-loop mismatch protection method is implemented that enables the PA to sustain a 20:1 load VSWR at full power. The circuit enables faster protection lock-in by reducing the number of low-frequency poles in the loop response.