Switched-mode power amplifier using lumped element impedance inverter for parallel combining

• US 20050007194A1
• Filed: 07/08/2003
• Published: 01/13/2005
• Est. Priority Date: 07/08/2003
• Status: Active Grant

• Current Assignee: Zarbana Digital Fund LLC (Intellectual Ventures LLC)
• Original Assignee: Seven Generations Energy Ltd.
• Inventors: Grundlingh, Johan M.
• Granted Patent: US 6,879,209 B2
• Time in Patent Office: Days
• US Class Current: 330/251
• CPC Class Codes: H03F 1/0294 using vector summing of two or more constant amplitude phase-modulated signals
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/391 the output circuit of an amplifying stage comprising an LC-network
• CPC Class Codes: H03F 2200/402 A series resonance being added in shunt in the output circuit, e.g. base, gate, of an 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 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602

Abstract

A switched-mode Class F power amplifier is provided for parallel connection with at least one other like amplifier, within a Chireix architecture, for combining the signals output therefrom. An input component includes at least one active device configured to be alternately switched by a signal input thereto to present an amplified signal corresponding to the input signal and constituting a low output impedance voltage source. A lumped element impedance inverter is provided between the input component and an output resonator component, the impedance inverter being configured for transforming the low output impedance voltage source to instead constitute a high output impedance current source configured for said parallel connection. In accordance with the invention, the negative reactive component values required by the impedance inverter are eliminated and effectively provided by incorporating those values into pre-selected reactive components of the input and output components. Further, a source-drain parasitic capacitance across the active device is eliminated by one or more pre-selected reactive components of the input component, the value(s) of which effectively compensate for the parasitic capacitance.

Claims

1. A switched-mode Class F power amplifier configured for parallel connection with at least one other said amplifier for combining signals output from such parallel connected amplifiers, said amplifier comprising:

(a) an input component comprising at least one active device configured to be alternately switched by a signal input thereto to present an amplified signal corresponding to said input signal, said amplified signal constituting a low output impedance voltage source;

(b) an output resonator component; and

,

(c) a lumped element impedance inverter connected between said input component and said output component, said impedance inverter configured for transforming said low output impedance voltage source so as to constitute a high output impedance current source, and said high output impedance current source configured for said parallel connection;

wherein negative reactive component values theoretically required by said impedance inverter are actually incorporated into pre-selected reactive components of said input and output components.

2. A switched-mode power amplifier according to claim 1 wherein said input signal is an analog phase modulated signal.

8. The switched-mode power amplifier according to claim 1, wherein the input component comprises a first inductor and a first capacitor, connected in series and electrically connected to the input of the impedance inverter.

9. The switched-mode power amplifier according to claim 8, wherein the output component comprises a second inductor and a second capacitor, connected in series and electrically connected to the output of the impedance inverter.

10. The switched-mode power amplifier according to claim 9, wherein the values for each of the first inductor, first capacitor, second inductor and second capacitor are selected in order to compensate for the negative reactive component values theoretically required but not otherwise included in the amplifier.

3. (Cancelled).

4. A method for producing a switched-mode power amplifier, said method comprising:

(a) designing a theoretical lumped-element impedance inverter configured to transform a low output impedance voltage source into a high output impedance current source, such ideal impedance inverter incorporating theoretically negative reactive component values;

(b) adding an input component comprising at least one active device configured to be alternately switched by an input signal thereto to present an amplified signal corresponding to said input signal, said amplified signal constituting a low output impedance voltage source;

(c) adding an output resonator component; and

(d) adjusting values of one or more elements coupled to the input and output components such that the theoretically negative reactive components may be eliminated, and eliminating the theoretically negative reactive components from the design.

5. A method according to claim 4 whereby said input signal is an analog phase modulated signal.

11. The method of claim 4, further comprising manufacturing the switched-mode power amplifier.

12. The method of claim 11, wherein the input component comprises a first inductor and a first capacitor, connected in series and electrically connected to the input of the impedance inverter.

13. The method of claim 12, wherein the output component comprises a second inductor and a second capacitor, connected in series and electrically connected to the output of the impedance inverter.

14. The method of claim 13, further comprising the step of selecting the values for each of the first inductor, first capacitor, second inductor and second capacitor in order to compensate for the negative reactive component values theoretically required but not present in the manufactured amplifier.

6. (Cancelled).

7. A plurality of switched-mode Class F power amplifiers in parallel connection for combining signals output from said amplifiers, said parallel-connected amplifiers comprising:

(a) an input component for each of said plurality of amplifiers, each said input component comprising at least one active device configured to be alternately switched by a signal input thereto to present an amplified signal corresponding to said input signal, said amplified signal constituting a low output impedance voltage source;

(b) a common output resonator component for said plurality of amplifiers; and

,

(c) a lumped element impedance inverter for each of said plurality of amplifiers between said input component and said output component, said impedance inverter configured for transforming said low output impedance voltage source so as to constitute a high output impedance current source and said high output impedance current source configured for said parallel connection;

wherein negative reactive component values required by said impedance inverter are eliminated and effectively provided by incorporating said values into pre-selected reactive components of said input and output components.