Patent ID: 8884714

Claim:
A multi-mode polar transmitter comprising: a filter configured to receive a polar modulated signal and to provide an amplitude signal; a first amplifier; a second amplifier; and a switch to be coupled to said filter and configured to selectively provide one of said first and second amplifiers the amplitude signal; each amplifier including a bias interface circuit comprising a first substrate comprising a first material and a second substrate comprising a second material different from the first material, a first transistor on said first substrate and having a control terminal configured to receive a bias current, and a first conduction terminal configured to provide a power supply signal, and a second transistor on said second substrate and having a control terminal to be coupled to the first conduction terminal of said first transistor and being configured to receive the amplitude signal, a phase modulated carrier signal, and the power supply signal, and a first conduction terminal configured to provide a combined waveform of the amplitude signal, the phase modulated carrier signal, and the power supply signal.