Chireix architecture using low impedance amplifiers

• US 20040075492A1
• Filed: 10/16/2002
• Published: 04/22/2004
• Est. Priority Date: 10/16/2002
• Status: Active Grant

• Current Assignee: Zarbana Digital Fund LLC (Intellectual Ventures LLC)
• Original Assignee: J.s. Wight, Inc., Seven Generations Energy Ltd.
• Inventors: Wight, James Stuart
• Granted Patent: US 6,836,183 B2
• Time in Patent Office: Days
• US Class Current: 330/124R
• CPC Class Codes: H03C 1/50 by converting angle modulation to amplitude modulation H03C1/28 - H03C1/34, H03C1/46, H03C1/48 take precedence
• CPC Class Codes: H03F 1/0294 using vector summing of two or more constant amplitude phase-modulated signals
• CPC Class Codes: H03F 2200/537 A transformer being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2200/541 Transformer coupled at the output of an amplifier
• CPC Class Codes: H03F 2203/21157 A filter circuit being added at the output of a power amplifier stage
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/217 Class D power amplifiers; Switching amplifiers
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers

Abstract

Circuits and methods for use in amplifying amplitude and phase modulated signals. A circuit uses a combiner with dual parallel signal amplifiers feeding it. The signal amplifiers have a low output impedance while the combiner does not provide any isolation between its inputs from the signal amplifiers. As in other Chireix architectures, the signals from the signal amplifiers are phase modulated prior to being fed to the combiner. The combiner then combines these two signals and, depending on how these two signals are combined, the resulting output of the combiner is amplitude modulated. The signal amplifiers may be Class D or Class F amplifiers to provide high efficiency amplification of the signals.

Claims

1. A circuit for providing amplification to signals, the circuit comprising:

a signal combiner;

at least two signal amplifiers each receiving and amplifying a signal, said signal amplifiers being coupled in parallel to said combiner, each of said signal amplifiers having a low output impedance and acting as a voltage source,

wherein

each signal received and amplified by each of said signal amplifiers is phase modulated;

outputs of each of said signal amplifiers are added by said combiner to produce a resulting signal; and

amplitude modulation of said resulting signal from said combiner is achieved by an addition of said outputs.

2. A circuit according to claim 1 wherein said combiner provides minimum isolation between said outputs of said signal amplifiers.

3. A circuit according to claim 1 wherein said combiner provides no isolation between said outputs of said signal amplifiers.

4. A circuit according to claim 3 wherein said combiner is a modified balanced magnetic transformer, said transformer being devoid of a center tap to ground connection, said signal amplifier outputs being coupled to terminals of an input winding of said transformer.

5. A circuit according to claim 3 wherein said combiner is a modified Wilkinson combiner with none of said outputs of said signal amplifiers being connected to an isolating resistor.

6. A circuit according to claim 1 wherein each of said amplifiers has switch mode operation.

7. A circuit according to claim 6 wherein each of said amplifiers is chosen from a group comprising:

class D signal amplifiers; and

class F signal amplifiers.

8. A circuit according to claim 1 wherein all of said at least two signal amplifiers are of the same type.

9. A circuit for providing amplification to signals, the circuit comprising:

at least two signal amplifiers each receiving and amplifying a signal and each producing an amplifier output; and

an signal combiner receiving each of said amplifier outputs in parallel, said signal combiner providing no isolation between said amplifier outputs,

wherein

each signal received and amplified by each of said signal amplifiers is phase modulated;

said amplifier outputs are added by said combiner to produce a resulting signal; and

amplitude modulation of said resulting signal from said combiner is achieved by an addition of said amplifier outputs.

10. A circuit according to claim 9 wherein each of said signal amplifiers has a very low output impedance.

11. A circuit according to claim 10 wherein each of said signal amplifiers has switch mode operation.

12. A circuit according to claim 11 wherein each of said signal amplifiers is chosen from a group comprising:

class D signal amplifiers; and

class F signal amplifiers.

13. A circuit according to claim 9 wherein each of said signal amplifiers is chosen from a group comprising:

class D signal amplifiers; and

class F signal amplifiers.

14. A circuit according to claim 9 wherein said combiner is a modified balanced magnetic transformer, said transformer being devoid of a center tap to ground connection, said signal amplifier outputs being coupled to terminals of an input winding of said transformer.

15. A circuit according to claim 9 wherein said combiner is a modified Wilkinson combiner with none of said outputs of said signal amplifiers being connected to an isolating resistor.

16. A circuit according to claim 9 wherein all of said at least two signal amplifiers are of the same type.