RF transmitters with saturation detection and correction and methods therefor

• US 20040176049A1
• Filed: 03/22/2004
• Published: 09/09/2004
• Est. Priority Date: 03/13/2002
• Status: Active Grant

• Current Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Original Assignee: Dale Schwent, Patrick Pratt, Thomas Nagode
• Inventors: Pratt, Patrick, Schwent, Dale, Nagode, Thomas
• Granted Patent: US 7,079,819 B2
• Time in Patent Office: Days
• US Class Current: 455/90.3
• CPC Class Codes: H03F 1/0272 by using a signal derived from the output signal
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence

Abstract

Methods in radio communications devices having a transmitter with an integral control loop, and in other integral control systems, including generating a first error signal (210) based upon an amplifier output signal and a corrected reference signal, generating a second error (220) signal based on a closed loop integral control signal applied to a control input of the amplifier and based on an integral control reference signal, and generating the corrected reference signal (230) by correcting a reference signal based upon the first and second error signals.

Claims

1. A radio communications device, comprising:

a transmitter having a modulator with an output coupled to an input of an amplifier;

an integral control device having an integral control output coupled to a control input of the amplifier;

an error signal circuit having a feedback input coupled to an output of the amplifier, the error signal circuit having a corrected reference input and an error output coupled to an error input of the integral control device;

an integral control device controller having an input coupled to the integral control output of the integral control device, the integral control device controller having a controlled output coupled to the amplifier control input, the integral control device controller having a limit reference input;

a reference signal control circuit having a first input coupled to the first error output of the error signal circuit, an error output of the integral control device controller coupled a second reference control input of the reference signal control circuit;

a reference signal correction circuit having a reference input, a reference control output of the reference signal control circuit coupled to a reference control input of the reference signal correction circuit.

2. The radio communications device of claim 1, the reference signal control circuit having a threshold input.

3. The radio communications device of claim 2, the reference signal control circuit for providing a corrected reference signal to the reference signal correction circuit if an error signal of the error signal circuit exceeds a saturation threshold of the reference signal control circuit.

4. The radio communications device of claim 1, the reference signal control circuit and the reference signal correction circuit for adjusting a corrected reference signal to the error signal circuit by an amount approximately equal to an error signal of the error signal circuit.

5. The radio communications device of claim 1, the reference signal control circuit and the reference signal correction circuit for adjusting a corrected reference signal to the error signal circuit by an amount greater than an error signal of the error signal circuit.

6. The radio communications device of claim 1, the reference signal control circuit and the reference signal correction circuit for adjusting a corrected reference signal to the error signal circuit by an amount less than an error signal of the error signal circuit.

7. The radio communications device of claim 1, the integral control device controller for limiting a control signal input to the amplifier based on a limit reference input of the integral control device controller.

8. The radio communications device of claim 1, the transmitter has a digital control loop, the reference signal control circuit and the reference signal correction circuit for adjusting a corrected reference signal to the error signal circuit based upon an error signal of the integral control device controller and an error signal the error signal circuit.