An amplifier system is provided that switches between a linear mode of operation, an envelope tracking mode of operation and a polar mode of operation. The amplifier system switches between modes of operation based upon a characteristic of an input signal relative to a first threshold level and a second threshold level. A mode selector selects the operation mode by transmitting an amplitude modulated signal plus a variable headroom voltage to a supply terminal of a power amplifier during the envelope tracking mode, an amplitude modulated signal to the supply terminal and phase modulated input signal during the polar mode and a substantially constant amplitude signal to the supply terminal during the linear mode.

Multi-mode amplifier system

The present invention, generally speaking, provides methods and apparatus for producing an amplitude modulated communications signal, in which a constant-envelope carrier signal is modified in response to a power control signal to produce a modified constant-envelope carrier signal. The modified constant-envelope carrier signal is amplified in response to an amplitude modulation signal to produce a communications signal having amplitude modulation and having an average output power proportional to a signal level of the modified constant-envelope carrier signal. This manner of operation allows wide dynamic range of average output power to be achieved. Because amplitude modulation is applied after amplitude varying circuitry used to produce the modified constant-envelope carrier signal, the amplitude modulation is unaffected by possible non-linearities of such circuitry. In accordance with another aspect of the invention, operation in the foregoing manner at comparatively low average output power levels is combined with switch mode operation at comparatively high average output power levels, enabling high overall efficiency to be achieved. Hence, the disclosed modulator and amplifier combination, in addition to supporting very low power signals, also supports high power signals.

Communications signal amplifiers having independent power control and amplitude modulation

Certain embodiments of the invention may be found in a method and system for minimizing power consumption in a communication system. Exemplary aspects of the invention may comprise configuring a supply voltage of an amplifier to enable communication of data using a first communication protocol during a first timeslot in a TDM frame, reconfiguring the supply voltage of the amplifier to enable communication of data using a different communication protocol, and adjusting the supply voltage of the amplifier in proportion to the envelope of a baseband signal conforming to one of the communication protocols. The first and second communication protocols may conform to various communication protocols, such as WCDMA, HSDPA, HSUDPA, GSM, GPRS, EDGE, WiMAX, OFDM, UWB, ZigBee, and Bluetooth. The baseband signal may be delayed by a number of samples before being input into the amplifier.

Method and System for Minimizing Power Consumption in a Communication System

RF power transmission, modulation, and amplification embodiments

A radio frequency amplifier module ( 500 ) has a voltage monitor ( 546 ) that monitors an input supply voltage of an input power supply ( 534 ) and an adjustable power supply ( 512 ) that accepts power from the input power supply ( 534 ) and produces an adjustable power supply output that has a controllable voltage. The radio frequency amplifier module ( 500 ) further has an amplifier ( 402 ) that is supplied by the adjustable power supply output and that amplifies a radio frequency signal. The radio frequency amplifier module ( 500 ) also has an output controller ( 546 ) that is communicatively coupled to the voltage monitor and the adjustable power supply ( 512 ). The output controller ( 546 ) controls, in response to the input source voltage, the controllable voltage of the adjustable power supply output.

Amplifier with varying supply voltage and input attenuation based upon supply voltage

A highly efficient radio frequency (RF) transmitter provides both wide bandwidth and an extended power control range. The RF transmitter includes stage switching, bias adjustment, and drain supply modulation. These components are used to provide fine and coarse power control and EER envelope fluctuations. The RF transmitter is useful in wireless communications to increase both handset talk time and battery life.

Brian Eidson

Papers

RF transmitter with extended efficient power control range