Battery life extending technique for mobile wireless applications using bias level control

• US 6,757,526 B1
• Filed: 09/19/2000
• Issued: 06/29/2004
• Est. Priority Date: 04/25/1997
• Status: Expired due to Term

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Inventors: Taylor, Stewart S., Ruebusch, Ronald R., Sharp, Steven J., Hammond, Samuel W.
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): TRAN, TUAN A
• Application Number:
  US09/664,878
• Time in Patent Office: 1,379 Days
• Field of Search: 455/91, 455/115-116, 455/126-127, 455/127--12, 455/527, 455/572, 330/285, 330/297, 330/129, 330/296, 330/300, 330/291, 330/278
• US Class Current: 455/127.1
• CPC Class Codes: H03F 1/0233 by using a signal derived from the output signal, e.g. bootstrapping the voltage supply
• CPC Class Codes: H03F 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 1/0272 by using a signal derived from the output signal
• CPC Class Codes: H03F 2200/18 the bias of the gate of a FET being controlled by a control signal
• CPC Class Codes: H03F 2200/207 A hybrid coupler being used as power measuring circuit at the output of an amplifier circuit
• CPC Class Codes: H03F 2200/411 the output amplifying stage of an amplifier comprising two power stages
• CPC Class Codes: H03G 3/3036 in high-frequency amplifiers or in frequency-changers H03G3/3052, H03G3/32, H03G3/34 take precedence

Abstract

An operating voltage applied to a transmitter'"'"'s power amplifier in a mobile wireless transceiver is dynamically controlled so as to improve the efficiency of the transmitter at all output power levels. In one embodiment, the bias current levels within the transmitter are also varied to optimize the efficiency of the transmitter at all output power levels. In a preferred embodiment, a highly efficient switching regulator is controlled by a control circuit to adjust the operating voltage and/or bias current for the power amplifier in the transmitter. The control circuit has as its input any of a variety of signals which reflect the actual output power of the transmitter, the desired output power, or the output voltage swing of the transmitter.

Claims

1. A mobile wireless device comprising:

an amplifier connected to receive an input signal to be transmitted by the mobile wireless device, said amplifier having an amplifier output terminal, said amplifier including at least one transistor;

a voltage regulator having an input terminal coupled to receive a DC voltage provided by a battery, and an output voltage terminal that sources a first variable voltage signal across terminals of a transistor of the amplifier;

a bias voltage generator that generates a second variable voltage signal that is provided to an input of a transistor of the amplifier; and

a controller having an input terminal connected to receive a first signal related to an output level of said amplifier, wherein the controller provides a second signal to the voltage regulator that determines the first variable voltage signal, and a third signal to the bias voltage generator that determines the second variable voltage signal, wherein the second and third signals are dependent on a value of the first signal.

2. The mobile wireless device of claim 1, wherein the voltage regulator is a switching regulator.

3. The mobile wireless device of claim 1, wherein the first signal is based on a signal output by the amplifier.

4. The mobile wireless device of claim 1, wherein the first signal is based on a signal received from another transmitting device.

5. A method for controlling a wireless device comprising:

amplifying a signal for transmission by the wireless device, said amplifying performed in an amplifier including at least one transistor;

receiving a first signal from another transmitting device;

controlling a voltage regulator that receives a voltage input from a battery of the wireless device, wherein the voltage regulator sources a first variable voltage signal that is applied across terminals of the at least one transistor, said first variable voltage signal being dependent on the first signal; and

controlling a bias circuit that provides a second variable voltage signal to an input of the at least one transistor, said second variable voltage signal being dependent on the first signal.

6. A method for controlling a wireless device comprising:

amplifying a signal for transmission by the wireless device, said amplifying performed in an amplifier including at least one transistor;

sampling the signal transmitted by the amplifier;

controlling a voltage regulator that receives a voltage input from a battery of the wireless device, wherein the voltage regulator sources a first variable voltage signal that is applied across the terminals of the at least one transistor, said first variable voltage signal being dependent on the sampled signal; and

controlling a bias circuit that provides a second variable voltage signal to an input of the at least one transistor, said second variable voltage signal being dependent on the sampled signal.