A 5.8 GHz class-AB power amplifier with 25.4 dBm saturation power and 29.7% PAE

Abstract

In this paper, an effective and succinct radio-frequency (RF) grounding technique for class-AB power amplifier (PA) is presented. The proposed technique employs a grounding path, resonant with a capacitor in series at the center of the fundamental and second-order harmonic frequencies, between the critical ground nodes, to ensure a low impedance path. The power loss due to imperfect grounding is then reduced by 2 dB, and the saturated output power and power added efficiency (PAE) are therefore significantly improved. A fully integrated 5.8-GHz PA with the proposed technique is designed and implemented in a 65-nm CMOS process. Measured result shows a saturated output power of 25.4 dBm and a peak PAE of 29.7%, while with only 2.5 V of supply voltage.