A Monolithic 2.8 V, 3.2 W Silicon Bipolar Power Amplifier With 54 % Pae At 900 Mhz

This work presents a balanced two-stage monolithic power amplifier in Si bipolar technology for 0.8-1GHz. On-chip transformers are used as input-balun as well as for interstage matching. A closed-loop bias circuit is introduced to diminish break-down effects and increase the maximum usable supply voltage.The chip is operating from 2.8V to 4.5V. At 2.8V the output power is 3.2W with a power-added efficiency of 54%. The maximum output power of 7.7W with an efficiency of 57% is achieved at 4.5V supply voltage. The small-signal gain is 38dB.