Waste energy control and management in power amplifiers

• US 5,638,024 A
• Filed: 06/07/1995
• Issued: 06/10/1997
• Est. Priority Date: 01/11/1994
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Dent, Paul W., Lampe, Ross W.
• Primary Examiner(s): MOTTOLA, STEVEN J
• Application Number:
  US08/472,662
• Time in Patent Office: 734 Days
• Field of Search: 330/84, 330/124 R, 330/149, 330/295, 455/114, 455/126
• US Class Current: 330/84
• CPC Class Codes: H03F 1/0294 using vector summing of two or more constant amplitude phase-modulated signals
• CPC Class Codes: H03F 1/3229 using a loop for error extraction and another loop for error subtraction
• CPC Class Codes: H03F 1/3252 using multiple parallel paths between input and output H03F1/3258, H03F1/3282, H03F1/3294 take precedence
• CPC Class Codes: H03F 1/34 Negative-feedback-circuit arrangements with or without positive feedback H03F1/02 - H03F1/30, H03F1/38 - H03F1/50, H03F3/50 take precedence ; for rejection of common mode signals H03F3/45479
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers
• CPC Class Codes: H04B 1/04 Circuits
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths
• CPC Class Codes: H04B 1/1607 Supply circuits converters H02M; filters therefor H02M1/14; voltage stabilisers G05F1/46
• CPC Class Codes: H04B 1/52 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
• CPC Class Codes: H04B 2001/0433 with linearisation using feedback

Abstract

An amplifying apparatus for linearly amplifying a desired signal using a pair of coupled non-linear amplifiers is disclosed. The amplifying apparatus comprises a limiter for separating amplitude variations from the desired signal and producing a constant amplitude signal bearing the phase of the desired signal and an amplitude related signal. In addition, a drive signal generater produces two drive signals each dependent on the constant amplitude signal and the amplitude related signal such that each drive signal depends on the phase of the desired signal and such that the sum of the squares of the amplitudes of the drive signals is constant. Finally, a coupler couples the two drive signals to produce two constant amplitude signals for driving the pair of non-linear power amplifiers and for coupling the outputs of the power amplifiers to produce two amplified output signals, one of which is the linearly amplified desired signal and the other of which is a waste energy signal.

Claims

1. An amplifying apparatus for linearly amplifying a plurality of input signals to produce a plurality of desired amplified output signals using a plurality of coupled non-linear power amplifiers, comprising:

input combining means for combining said input signals to produce a plurality of combined signals for amplification by said non-linear amplifiers;

output combining means for combining outputs of said non-linear amplifiers to produce a plurality of combined output signals;

multi-channel Cartesian feedback means for processing selected combined output signals to produce a plurality of feedback signals;

multi-channel comparator means for comparing the input signals with the feedback signals to produce a plurality of error signals and for filtering the error signals;

multi-channel quadrature modulator means for converting the filtered error signals to drive signals for said non-linear amplifiers such that a number of the combined output signals correspond to the desired amplified output signals and any remaining combined output signals are waste energy signals.

2. The amplifying apparatus of claim 1, wherein a total number of non-linear amplifiers exceeds a total number of input signals and said output combining means produces a total number of waste energy signals, wherein the total number of waste energy signals equals a difference between the total number of non-linear amplifiers and the total number of input signals.

3. The amplifying apparatus of claim 2, wherein the waste energy signals are dissipated in dissipating means to avoid corruption of the desired output signals by intermodulation signals.