A class A/B low power amplifier for wireless sensor networks

Abstract

In a dense ad-hoc wireless sensor network, the transmit power is comparable to the circuit power. Linear power amplifiers, which require lower drive power as compared to their switching counterparts, now become viable candidates. This paper presents a class A/B low power amplifier suitable for an ad-hoc wireless sensor network. The amplifier is implemented in a 0.13 /spl mu/m CMOS process and operates with a nominal 1.2 V supply. A capacitive transformer is used to match the antenna to the power amplifier for maximum efficiency. The amplifier achieves 35% drain efficiency while delivering 2.6 mW at 1.92 GHz. With 1.5 V supply, the power amplifier delivers 4.8 mW with 38% drain efficiency.