Method and system for preventing an amplifier overload condition in a hybrid matrix amplifier array

• US 5,783,969 A
• Filed: 09/04/1996
• Issued: 07/21/1998
• Est. Priority Date: 09/04/1996
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Luz, Yuda Yehuda
• Primary Examiner(s): Mottola, Steven
• Application Number:
  US08/708,864
• Time in Patent Office: 685 Days
• Field of Search: 330/53, 330/124 D, 330/124 R, 330/207 D, 330/286, 330/295, 330/298
• US Class Current: 330/124.00R
• CPC Class Codes: H03F 1/52 Circuit arrangements for protecting such amplifiers monitoring arrangements G01R31/28; increasing reliability in communication systems, e.g. using redundancy H04B1/74
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers

Abstract

In a hybrid matrix amplifier array (100), the amplitude of each of a plurality of input signals is measured (132-136, 202). In response to the signal amplitude measurements, an overload condition that will result in an amplifier overload in said hybrid matrix amplifier array is estimated (204, 206, 138). In response to the estimation of the overload condition, the signal amplitude of at least one of the plurality of input signals is modified to prevent the overload condition in the hybrid matrix amplifier array. An overload condition may be estimated if the sum of the amplitudes of the input signals exceeds a threshold (206). In one embodiment, all input signals are modified by proportionately reducing the amplitude of each of the plurality of input signals (304).

Claims

1. A method for preventing an amplifier overload condition in a hybrid matrix amplifier array comprising the steps of:

measuring signal amplitude of each of a plurality of input signals;

in response to said signal amplitude measurements, estimating an overload condition that will result in an amplifier overload in said hybrid matrix amplifier array; and

in response to estimating said overload condition, modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition in said hybrid matrix amplifier array.

2. The method for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 1 wherein said step of estimating an overload condition that will result in an amplifier overload in said hybrid matrix amplifier array includes detecting that the sum of an absolute value of each of said measured signal amplitudes exceeds an overload threshold.

3. The method for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 1 wherein said step of modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes reducing the amplitude of a minimum number of input signals that can be reduced in amplitude to prevent said overload condition.

4. The method for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 1 wherein said step of modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes reducing the amplitude of a lowest amplitude input signal that can be reduced in amplitude to prevent said overload condition.

5. The method for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 3 wherein said step of modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes reducing the amplitude of a group of input signals, wherein said group of input signals includes the minimum number of input signals with the minimum summed amplitude that can be reduced to eliminate said amplifier overload condition.

6. The method for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 1 wherein said step of modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes reducing the amplitude of all of said input signals to prevent said overload condition.

7. The method for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 1 wherein said step of modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes proportionately reducing the amplitude of all of said input signals to prevent said overload condition.

8. A system for preventing an amplifier overload condition in a hybrid matrix amplifier array comprising:

means for measuring signal amplitude of each of a plurality of input signals;

means for estimating an overload condition that will result in an amplifier overload in said hybrid matrix amplifier array in response to said signal amplitude measurements; and

means for modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition in said hybrid matrix amplifier array in response to estimating said overload condition.

9. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 8 wherein said means for estimating an overload condition that will result in an amplifier overload in said hybrid matrix amplifier array includes means for detecting that the sum of an absolute value of each of said measured signal amplitudes exceeds an overload threshold.

10. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 8 wherein said means for modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes means for reducing the amplitude of a minimum number of input signals that can be reduced in amplitude to prevent said overload condition.

11. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 8 wherein said means for modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes means for reducing the amplitude of a lowest amplitude input signal that can be reduced in amplitude to prevent said overload condition.

12. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 10 wherein said means for modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes means for reducing the amplitude of a group of input signals, wherein said group of input signals includes the minimum number of input signals with the minimum summed amplitude that can be reduced to eliminate said amplifier overload condition.

13. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 8 wherein said means for modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes means for reducing the amplitude of all of said input signals to prevent said overload condition.

14. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 8 wherein said means for modifying said signal amplitude of at least one of said plurality of input signals to prevent said overload condition includes means for proportionately reducing the amplitude of all of said input signals to prevent said overload condition.

15. A system for preventing an amplifier overload condition in a hybrid matrix amplifier array comprising:

a plurality of input signal amplitude estimators, each serially coupled to a plurality of input signals;

a hybrid matrix amplifier array overload condition detector coupled to each of said plurality of input signal power estimators for producing an overload condition signal in response to detecting an amplifier overload condition; and

at least one attenuator serially coupled to one of said input signals for reducing the power of said input signal in response to said overload condition signal, wherein said amplifier overload condition is eliminated.

16. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 15 wherein said hybrid matrix amplifier array overload condition detector includes:

a summer for producing a total amplitude signal equal to the sum the absolute values of all input signal amplitudes received from said input signal amplitude estimators; and

a comparator for indicating an amplifier overload condition in response to said total amplitude signal exceeding a threshold.

17. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 15 wherein said at least one attenuator is a clipping circuit that includes means for reducing the amplitude of said serially coupled input signal in response to said overload condition signal and amplitudes of others of said plurality of input signals.

18. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 15 wherein each of said plurality of input signals is a series of digital samples.

19. The system for preventing an amplifier overload condition in a hybrid matrix amplifier array according to claim 15 wherein each of said plurality of input signals is serially coupled to one of said attenuators, and each of said attenuators includes amplitude attenuation means for reducing the amplitude of each of said plurality of input signals by a proportionate amount to eliminate said amplifier overload condition.