Dualband power amplifier control using a single power amplifier controller

• US 6,216,012 B1
• Filed: 11/07/1997
• Issued: 04/10/2001
• Est. Priority Date: 11/07/1997
• Status: Expired due to Term

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Jensen, Niels J.
• Primary Examiner(s): Vo, Nguyen
• Assistant Examiner(s): RAMOS FELICIANO, ELISEO
• Application Number:
  US08/965,843
• Time in Patent Office: 1,250 Days
• Field of Search: 455/553, 455/103, 455/126, 455/552, 455/127, 455/84, 455/86, 455/426, 455/572, 330/126, 330/129
• US Class Current: 455/553.1
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H03G 3/3047 for intermittent signals, e.g. burst signals
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/04 Circuits
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 2001/0408 with power amplifiers
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A system having dualband power amplifier control in a dualband phone is provided using a single power amplifier controller. The dualband phone includes two power amplifiers, where each power amplifier amplifies the power of a signal transmitted at a different frequency band. A power amplifier controller is provided for controlling the amount of amplification performed by both of the power amplifiers, and a power amplifier switching device is connected to the power amplifier controller for switching the connection of the power amplifier controller between the two power amplifiers. The system further includes a processing device which monitors the quality and strength of the received signal transmitted by various base stations in the transmission region of the dualband phone. The processing device instructs the power amplifier switching device to switch its connection between the two power amplifiers based upon a determination of which frequency band provides the optimal balance between signal quality and signal strength, and the dualband phone then transmits its signal within the selected optimal frequency band. The system measures the power of the signal transmitted from the power amplifier connected to the power amplifier controller and feeds the measured power value back to the power amplifier controller, so that the power amplifier controller may adjust the voltage driving the power amplifier connected thereto based upon any differences found between the desired power output of the connected power amplifier and the measured power output.

Claims

1. A dualband phone having dualband amplifier control using a single power amplifier controller, comprising:

a first power amplifier for amplifying the power of a signal transmitted at a first frequency band;

a second power amplifier for amplifying the power of a signal transmitted at a second frequency band;

a power amplifier controller for controlling the amount of amplification performed by one of said first and second power amplifier;

a single switch connected to said power amplifier controller for switching the connection of said power amplifier controller between said first and second power amplifier; and

a processing means for monitoring the quality and strength of a received signal from a base station and instructing said switch to switch its connection between said first and second power amplifier based upon a determination of which of said first and second frequency bands provides an optimal balance between signal quality and signal strength.

2. The dualband phone of claim 1, wherein said processing means includes a stored predetermined relationship between signal strength and a voltage driving said first and second power amplifiers;

said processing means further instructing said power amplifier controller to adjust the voltage driving said first and second power amplifiers according to a desired signal strength.

3. The dualband phone of claim 1, wherein said processing means monitors the quality and strength of the received signal for each duty cycle of the phone and instructs said single switch which of said first and second power amplifier to connect to said amplifier controller for each duty cycle.

4. The dualband phone of claim 1, further comprising:

a first power measuring means for measuring the power of the signal transmitted from said first power amplifier;

a second power measuring means for measuring the power of the signal transmitted from said second power amplifier; and

a feedback switching means for selectively connecting one of said first and second power measuring means to said power amplifier controller;

wherein said feedback switching means operates in conjunction with said single switch so that said first power measuring means is connected to said power amplifier controller when said power amplifier controller is connected to said first power amplifier and said second power measuring means is connected to said power amplifier controller when said power amplifier controller is connected to said second power amplifier.

5. The dualband phone of claim 4, wherein said power amplifier controller adjust the voltage driving the power amplifier connected thereto based upon a difference between a desired power output and the power measured by one of said first and second power measuring means.

6. The dualband phone of claim 4, further comprising:

a transmitting antenna connected to the outputs from said first and second power amplifiers;

a first directional coupler positioned between said transmitting antenna and said first power measuring means; and

a second directional coupler positioned between said transmitting antenna and said second power measuring means;

wherein said first and second directional couplers prevent any signals reflected back from said transmitting antenna from entering said first and second power measuring means, respectively.

7. The dualband phone of claim 1, further comprising a voltage-to-current amplifier positioned between said power amplifier controller and said single switch when said first and second power amplifiers are current driven.

8. A method for controlling the power of a signal transmitted from a dualband telephone to a base station, comprising the steps of:

monitoring the quality and strength of signals received at the dualband telephone from the base station and at the base station from the dualband telephone;

determining which frequency band of the dualband telephone will provide the optimal balance between signal quality and signal strength while transmitting the signal to the base station based upon the quality and strength of the signals received by at least one of the dualband phone and the base station;

switching the connection of a power amplifier controller to one of a first power amplifier amplifying the power of signal transmitted at a first frequency band and a second power amplifier amplifying the power of a signal transmitted a second frequency band, wherein the connection is switched depending upon which frequency band will provide the optimal balance between signal quality and signal strength;

controlling the amount of amplification performed by the connected one of said first power amplifier and said second power amplifier based upon a desired signal strength.

9. The method for controlling the power of a signal transmitted from a dualband telephone of claim 8, wherein the amount of amplification performed is controlled by adjusting a voltage driving said first and second power amplifiers according to the desired signal strength.

10. The method for controlling the power of a signal transmitted from a dualband telephone of claim 8, wherein the quality and strength of the received signals is monitored during each duty cycle of the received signals and the connection between said power amplifier controller and one of said first power amplifier and said second power amplifier is determined for each duty cycle.

11. The method for controlling the power of a signal transmitted from a dualband telephone of claim 8, further comprising the steps of:

measuring the power of the signal transmitted from the connected one of said first power amplifier and said second power amplifier;

delivering the measured power of the transmitted signal back to said power amplifier controller; and

adjusting the voltage driving the selected power amplifier based upon a difference between the desired power output of the selected power amplifier and the measured power of the transmitted signal fed back to said power amplifier controller.

12. A system for controlling the power of a signal transmitted from a multiband transmitter, comprising:

a plurality of power amplifiers for amplifying the power of a signal transmitted at a plurality of frequency bands;

wherein each of said plurality of power amplifiers amplifies the power of a signal transmitted at a different frequency band;

a power amplifier controller for controlling the amount of amplification performed by one of said plurality of power amplifiers;

a single switch connected to said power amplifier controller for switching the connection of said power amplifier controller between said plurality of power amplifiers; and

a processing means for monitoring the quality and strength of a received signal from a base station and instructing said single switch to switch its connection between said plurality of power amplifiers based upon a determination of which of said plurality of frequency bands provides an optimal balance between signal quality and signal strength.

13. The system for controlling the power of a signal transmitted from a multiband transmitter of claim 12, wherein said processing means includes a stored predetermined relationship between signal strength and a voltage driving said plurality of power amplifiers;

said processing means further instructing said power amplifier controller to adjust the voltage driving said plurality of power amplifiers according to the desired signal strength.

14. The system for controlling the power of a signal transmitted from a multiband transmitter of claim 12, wherein said processing means monitors the quality and strength of the received signal for each duty cycle of the received signal and instructs said single switch which of said plurality of power amplifiers to connect to said power amplifier controller for each duty cycle.

15. The system for controlling the power of a signal transmitted from a multiband transmitter of claim 12, further comprising:

a plurality of power measuring means for measuring the power of the signal transmitted from said plurality of power amplifiers;

wherein each one of said plurality of power amplifiers is associated with a respective one of said plurality of power measuring means; and

a feedback switching means for selectively connecting one of said plurality of power measuring means to said power amplifier controller;

wherein said feedback switching means operates in conjunction with said single switch so that a respective one of said plurality of power measuring means is connected to said power amplifier controller along with its associated one of said plurality of power amplifiers.

16. The system for controlling the power of a signal transmitted from a multiband transmitter of claim 15, wherein said power amplifier controller adjust the voltage driving the power amplifier connected thereto based upon a difference between a desired power output and the power measured by one of said plurality of power measuring means.

17. The system for controlling the power of a signal transmitted from a multiband transmitter of claim 15, further comprising:

a transmitting antenna connected to the outputs from said plurality of power amplifiers; and

a plurality of directional couplers positioned between said transmitting antenna and said plurality of power measuring means;

wherein each one of said plurality of directional couplers is associated with a respective one of said power measuring means;

wherein said plurality of directional couplers prevent any signals reflected back from said transmitting antenna from entering said plurality of power measuring means, respectively.

18. The system for controlling the power of a signal transmitted from a multiband transmitter of claim 12, further comprising a voltage-to-current amplifier positioned between said power amplifier controller and said single switch when said power amplifiers are current driven.