DUAL-BAND, DUAL-MODE POWER AMPLIFIER WITH REDUCED POWER LOSS

摘要

A POWER AMPLIFIER CIRCUIT HAS A DRIVER AMPLIFIER STAGE INCLUDING A LOW BAND DRIVER AMPLIFIER AND A HIGH BAND DRIVER AMPLIFIER. A FINAL AMPLIFIER STAGE INCLUDES A LINEAR MODE AMPLIFIER FOR AMPLIFYING DIGITALLY. MODULATED; SIGNALS AND A SATURATED (NONLINEAR) MODE AMPLIFIER FOR AMPLIFYING FREQUENCY MODULATED (ANALOG) SIGNALS. A SWITCHING NETWORK INTERCONNECTS THE DRIVER AMPLIFIER STAGE AND THE FINAL AMPLIFIER STAGE. DEPENDING ON THE DESIRED MODE OF OPERATION, AN APPROPRIATE DRIVER AMPLIFIER CAN BE COUPLED TO AN APPROPRIATE FINAL AMPLIFIER TO MOST EFFECTIVELY AND EFFICIENTLY AMPLIFY ANALOG OR DIGITAL RF SIGNALS IN EITHER OF A PLURALITY OF FREQUENCY BANDS. A MATCHING CIRCUIT IS COUPLED TO THE LINEAR MODE FINAL AMPLIFIER FOR IMPEDANCE MATCHING AND FOR SEPARATING D-AMPS (800 MHZ BAND) AND PCS (1900 MHZ BAND) DIGITAL SIGNALS. A POWER IMPEDANCE MATCHING CIRCUIT IS COUPLED TO THE OUTPUT OF THE SATURATED MODE FINAL AMPLIFIER. IN ONE EMBODIMENT, AN ISOLATOR IS COUPLED TO THE OUTPUT OF ONE OR MORE OF THE LOW BAND OR HIGH BAND OUTPUTS OF THE DIPLEX MATCHING CIRCUIT. IN THE LOW BAND ANALOG PATH, A DUPLEXER IS PROVIDED AHEAD OF THE COUPLING MEANS FOR REDUCING THE RF POWER REQUIREMENTS ON THE COUPLING MEANS. THE SWITCHING NETWORK AND INPUT FILTER STAGE MAY PRECEDE A DRIVER AMPLIFIER STAGE.