System and method for producing an amplified signal

• US 6,292,054 B1
• Filed: 11/19/1999
• Issued: 09/18/2001
• Est. Priority Date: 11/19/1999
• Status: Expired due to Term

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Ma, Zhengxiang, Polakos, Paul Anthony
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Choe, Henry
• Application Number:
  US09/444,319
• Time in Patent Office: 669 Days
• Field of Search: 330/124.R, 330/126, 330/295, 455/126, 455/103, 455/127, 375/296, 333/20, 333/17.2
• US Class Current: 330/126
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers

Abstract

A signal amplification system involves decomposing a signal into two or more parts, amplifying the parts and then combining the amplified parts to produce the amplified signal. The decomposition can be done such that the resulting parts have characteristics that are amenable to efficient amplification. For example, decomposition of the signal to be amplified can be done using at least one threshold. The first part of the signal to be amplified can be formed by the portion of the signal within the threshold. As such, because the first part forms a signal with a lower PAR, the first part of the signal can be amplified more efficiently than the original signal. The second part of the signal can be formed by the portion of the original signal beyond the threshold. Because the second part is mostly zero, the second part can also be amplified efficiently, for example with a class C type amplifier which does not dissipate any energy when the input signal is zero.

Claims

1. A method of producing an amplified signal, said method comprising:

decomposing a signal to be amplified into at least a first part and a second part using at least one amplitude threshold, wherein the first part includes a signal with a lower peak-to-average power ratio than the second part based on the amplitude threshold and the second part includes a signal with a higher peak-to-average power ratio than the first part based on the amplitude threshold;

amplifying said at least said first part and said second part to produce at least an amplified first part and an amplified second part; and

combining said at least said amplified first part and said amplified second part to produce an amplified signal.

2. The method of claim 1 wherein said decomposing further including:

providing said first part of said signal as being the portion of said signal within a threshold; and

providing said second part of said signal as being the portion of said signal beyond a threshold.

3. The method of claim 2 wherein said decomposing including:

detecting an amplitude for said signal; and

comparing said amplitude for said signal with said threshold.

4. The method of claim 2 wherein said amplifying including:

amplifying said first part with a first amplifier; and

amplifying said second part with a second amplifier.

5. The method of claim 2 further including:

upconverting said first part prior to amplification; and

upconverting said second part prior to amplification.

6. The method of claim 2 wherein said providing said first part including:

providing said first part having a reduced peak to average power ratio compared to said signal.

7. The method of claim 1 wherein said combining includes:

using a matched impedance network to combine said first part and said second part.

8. The method of claim 7 wherein said using includes:

using a directional coupler to combine said first part and said second part.

9. The method of claim 3 wherein said decomposing includes:

performing said decomposing of said signal in a baseband digital domain.

10. A signal amplification system comprising:

circuitry configured to decompose a signal to be amplified and at least produce a first part on a first path and a second part on a second path based on at least one amplitude threshold, wherein the first part includes a signal with a lower peak-to-average power ratio than the second part based on the amplitude threshold and the second part includes a signal with a higher peak-to-average power ratio than the first part based on the amplitude threshold;

a first amplifier on said first path receives said first part and amplifies said first part to produce an amplified first part;

a second amplifier on said second path receives said second part and amplifies said second part to produce an amplified second part; and

combining circuitry configured to receive said amplified first part and said amplified second part and to combine said amplified first part and said amplified second part to produce an amplified signal.

11. The system of claim 10 wherein said circuitry configured to compare an amplitude for said signal with a threshold and produce the portion of said signal within a threshold as said first part and produce the portion of said signal beyond a threshold as said second part.

12. The system of claim 10 wherein said circuitry is configured as at least part of a matched impedance network to combine said first part and said second part.

13. The system of claim 10 wherein said circuitry includes a directional coupler.