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

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.

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. 
     
     
       3. 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. 
 
     
     
       4. A method according to  claim 3  whereby said input signal is an analog phase modulated signal. 
     
     
       5. 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. 
 
     
     
       6. 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. 
     
     
       7. The switched-mode power amplifier according to  claim 6 , 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. 
     
     
       8. The switched-mode power amplifier according to  claim 7 , 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. 
     
     
       9. The method of  claim 3 , further comprising manufacturing the switched-mode power amplifier. 
     
     
       10. The method of  claim 9 , 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. 
     
     
       11. The method of  claim 10 , 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. 
     
     
       12. The method of  claim 11 , 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. 
     
     
       13. An apparatus, comprising:
 means for amplifying an input signal to generate a low output impedance voltage source by alternately switching an input component, wherein the input component includes at least one active device responsive to the input signal; and   means for transforming the low output impedance voltage source into a high output impedance current source using a lumped-element impedance inverter coupled to the means for amplifying;   wherein negative reactive component values theoretically required by the lumped-element impedance inverter include pre-selected reactive components; and   wherein the means for amplifying includes a first inductor means serially connected to a first capacitor means and electrically connected to an input of the lumped-element impedance inverter.   
     
     
       14. The apparatus of claim 13, further comprising:
 output resonator means coupled to both the means for amplifying and the means for transforming;   wherein the output resonator means includes a second inductor means serially connected to a second capacitor means and electrically connected to an output of the lumped-element impedance inverter.   
     
     
       15. The apparatus of claim 14, further comprising means for selecting the values for each of the first inductor means, the first capacitor means, the second inductor means, and the second capacitor means to compensate for the negative reactive component values theoretically required but not present in the apparatus. 
     
     
       16. An apparatus, comprising:
 means for amplifying an input signal;   means for resonating a resonant frequency, wherein the means for resonating is coupled to the means for amplifying; and   means for inverting an impedance, wherein the means for inverting is coupled between the means for amplifying and the means for resonating;   wherein the means for inverting includes means for transforming an output of the means for amplifying from a voltage source having a low output impedance into a current source having a high output impedance; and   wherein the means for inverting further includes one or more negative valued theoretical reactive components realized as one or more positive valued reactive components of at least one of the means for amplifying or the means for resonating, or a combination thereof.   
     
     
       17. The apparatus of claim 16, wherein the means for resonating comprises means for realizing an inductance serially connected to a means for realizing a capacitance, and wherein at least one of the means for realizing an inductance or the means for realizing a capacitance, or a combination thereof, incorporates a negative reactive component of the means for inverting. 
     
     
       18. An amplifier, comprising:
 an input component including at least one active device configured to be alternately switched by an input signal to generate a low output impedance voltage source; and   an impedance converter coupled between the input component and an output component and configured to generate a high output impedance current source in response to the low output impedance voltage source;   wherein the input component and the output component both include reactive components that eliminate negative reactive component values theoretically required by the impedance converter.   
     
     
       19. The amplifier of claim 18, wherein the input signal comprises an analog phase-modulated signal. 
     
     
       20. The amplifier of claim 18, wherein the input component comprises a first inductor serially connected to a first capacitor. 
     
     
       21. The amplifier of claim 20, wherein the output component comprises a second inductor serially connected to a second capacitor. 
     
     
       22. The amplifier of claim 21, wherein the first inductor, the first capacitor, the second inductor, and the second capacitor are selected to compensate for the negative reactive component values theoretically required but not present in the amplifier.