Fully integrated low-power SiGe power amplifier for biomedical applications

A full-integrated very low-power SiGe power amplifier (PA) is realised using the innovations for high performance, 0.25 mu m SiGe process. The behaviour of the amplifiers has been optimised for the 2.1-2.4 GHz frequency band for a higher 1 dB compression point and high efficiency at a lower supply voltage. The PA delivers an output power of 3.75 and 1.25 mW for 2 and 1 V, respectively. The PA measurements yielded the following parameters: gain of 13 dB, 1 dB compression point of 5.7 dBm, and power added efficiency of 30% for 2 V supply voltage. The PA circuit can go down to 1 V of supply voltage with a gain of 10 dB, 1 dB compression point of 1 dBm, and power added efficiency of 20%. For both supply voltages, the input and the output of the circuit give good reflection performance. With this performance, the PA circuit may be used for low-power biomedical implanted transceiver systems.