Patent ID: 7593698

Claim:
A polar modulated power amplifier circuit comprising: an amplitude modulation circuit adapted to: receive a phase modulated (PM) input signal; receive a first amplitude modulated (AM) input signal; provide a PM final stage signal, wherein an amplitude of the PM final stage signal is based on the first AM input signal, and a phase of the PM final stage signal is based on the PM input signal; and control the amplitude of the PM final stage signal to prevent a base-to-collector junction of a base and a collector from becoming forward biased; and a final amplifier stage: comprising: the base adapted to receive the PM final stage signal; and the collector adapted to receive a second AM input signal; and adapted to provide a polar modulated output signal, wherein an amplitude of the polar modulated output signal is based on the second AM input signal, and a phase of the polar modulated output signal is based on the PM final stage signal.