Switched-mode power amplifier integrally performing power combining

Abstract

A switched-mode power amplifier is configured for performing power amplification of a plurality of signals input thereto and integrally summing (combining) those signals. Conceptually, this is achieved by replacing the input winding of the transformer component of a transformer-coupled voltage switching amplifier with separate input components, one for each input signal, in similar manner to the configuration of the input components of a three-port combiner (trifilar). In a first transformer-containing category of embodiments of the invention, the input winding of the amplifier's transformer is comprised of a plurality of series-coupled windings, one for each of the plurality of input components/signals such that the input components constitute a series connection of low output impedance sources applied to the amplifier's resonator and load. This, in turn, provides a high level of isolation between the amplifier input components and results in a low level of loss. In a second non-transformer-containing category of embodiments of the invention, the transformer component is replaced by a transmission line impedance transformer, or a lumped element equivalent circuit, which transforms the low output impedance sources to high output impedance sources and those sources are connected in parallel (rather than in series per the first category of embodiments).

1. A switched-mode power amplifier configured for integrally amplifying and combining a plurality of analog phase modulated signals input thereto, said amplifier comprising:
 (a) an input component for each of said plurality of analog phase modulated input signals wherein each said input component comprises at least one active device configured to be alternately switched by an analog phase modulated input signal to present an amplified signal corresponding to said analog phase modulated input signal, said amplified signal constituting a low output impedance voltage source; 
 (b) an output resonator component; and, 
 (c) an impedance inverter between each said input component and said resonator component, said impedance inverter configured for transforming said low output impedance voltage source to a high output impedance current source, wherein said high output impedance sources are combined in parallel before being passed to said resonator component; 
 wherein said impedance inverter comprises a lumped element equivalent component to a quarter-wavelength transmission line:; 
 wherein said lumped element equivalent component comprises two or more of a series inductor, a series negative inductor, a shunt-to-ground inductor, a shunt-to-ground negative inductor, a series capacitor, a series negative capacitor, a shunt-to-ground capacitor, and a shunt-to-ground negative capacitor. 
 
     
     
       2. A switched-mode power amplifier according  claim 1 , wherein said lumped element equivalent component comprises a series inductor and two shunt-to-ground, negative inductors connected to each terminal end of said series inductor, said inductors being of equal absolute value. 
     
     
       3. A switched-mode power amplifier according to  claim 1 , wherein said lumped element equivalent component comprises two series negative inductors and a shunt-to-ground inductor between said series inductor, said inductors being of equal absolute value. 
     
     
       4. A switched-mode power amplifier according to  claim 1 , wherein said lumped element equivalent component comprises a series capacitor and two shunt-to-ground, negative capacitors connected to each terminal end of said series capacitor, said capacitors being of equal absolute value. 
     
     
       5. A switched-mode power amplifier according to  claim 1 , wherein said lumped element equivalent component comprises two series negative capacitors and a shunt-to-ground capacitor between said series capacitor, said capacitors being of equal absolute value. 
     
     
       6. A method for integrally amplifying and combining a plurality of analog phase modulated input signals to produce a single amplified, summation signal for input to a resonator component, said method comprising:
 a. amplifying each said analog phase modulated input signal by a separate amplifier input component to produce an amplified signal corresponding to an analog phase modulated input signal and constituting a low output impedance voltage source, said amplifying comprising applying said analog phase modulated input signal to at least one active device of said input component to cause alternate switching of said active device; and, 
 b. transforming each said low output impedance voltage source to a high output impedance current source; and, 
 c. combining said high output impedance sources in parallel to produce a single amplified, summation signal; 
 wherein said transforming is performed by an impedance inverter comprising a lumped element equivalent component to a quarter-wavelength transmission line; and 
 wherein said lumped element equivalent component comprises two or more of a series inductor, a series negative inductor, a shunt-to-ground inductor, a shunt-to-around negative inductor, a series capacitor, a series negative capacitor, a shunt-to-ground capacitor, and a shunt-to-around negative capacitor. 
 
     
     
       7. A method according to  claim 6 , whereby said lumped element equivalent component comprises a series inductor and two shunt-to ground, negative inductors of equal absolute value connected to each terminal end of said series inductance. 
     
     
       8. A method according to  claim 6 , whereby said lumped element equivalent component comprises two series negative inductors and a shunt-to-ground inductor between said series inductor, said inductors being of equal absolute value. 
     
     
       9. A method according to  claim 6 , whereby said lumped element equivalent component comprises a series capacitor and two shunt-to-ground, negative capacitors connected to each terminal end of said series capacitor, said capacitors being of equal absolute value. 
     
     
       10. A method according to  claim 6 , whereby said lumped element equivalent component comprises two series negative capacitors and a shunt-to-ground capacitor between said series capacitor, said capacitors being of equal absolute value. 
     
     
       11. A switched-mode power amplifier configured for integrally amplifying and combining a plurality of signals input thereto, said amplifier comprising:
 (a) an input component for each of said plurality of input signals wherein each said input component comprises at least one active device configured to be alternately switched by said input signal to present an amplified signal corresponding to said input signal, said amplified signal constituting a low output impedance voltage source; 
 (d)(b) an output resonator component; and, 
 (e)(c) an impedance inverter between each said input component and said resonator component, said impedance inverter configured for transforming said low output impedance voltage source to a high output impedance current source,; 
 wherein said high output impedance sources are combined in parallel before being passed to said resonator component; 
 wherein said impedance inverter comprises at least one of:
 (i) a series inductor and two shunt-to-ground, negative inductors connected to each terminal end of said series inductor, said inductors being of equal absolute value; 
 (iii)(ii) two series negative inductors and a shunt-to-ground inductor between said series inductor, said inductors being of equal absolute value; 
 (ii)(iii) a series capacitor and two shunt-to-ground, negative capacitors connected to each terminal end of said series capacitor, said capacitors being of equal absolute value; and 
 (iv) two series negative capacitors and a shunt-to-ground capacitor between said series capacitor, said capacitors being of equal absolute value. 
 
 
     
     
       12. A switched-mode power amplifier, comprising:
 a plurality of input components each associated with a corresponding input signal and configured to generate a low output impedance voltage source; and   an impedance inverter configured to convert the low output impedance voltage sources into high output impedance current sources;   wherein the impedance inverter includes a lumped element equivalent component to a quarter-wavelength transmission line; and   wherein the impedance inverter includes at least one of:
 a first circuit comprising a series inductor and two shunt-to-ground negative inductors; 
 a second circuit comprising a shunt-to-ground inductor and two negative series inductors; 
 a third circuit comprising a series capacitor and two shunt-to-ground negative capacitors; or 
 a fourth circuit comprising a shunt-to-ground capacitor and two negative series capacitor. 
   
     
     
       13. The switched-mode power amplifier of claim 12, wherein the plurality of input signals comprise analog phase-modulated signals. 
     
     
       14. The switched-mode power amplifier of claim 12, wherein each of the input components comprises at least one active device configured to be alternately switched by the corresponding input signal to generate a corresponding amplified signal. 
     
     
       15. The switched-mode power amplifier of claim 12, wherein the plurality of input signals comprise radio frequency (RF) signals. 
     
     
       16. The switched-mode power amplifier of claim 12,
 wherein the high output impedance current sources are configured to be combined in parallel to generate a summation signal.   
     
     
       17. The switched-mode power amplifier of claim 16, further comprising an output resonator configured to receive the summation signal. 
     
     
       18. A method, comprising:
 amplifying each of a plurality of input signals using a corresponding input component to produce a plurality of corresponding amplified signals;   converting each of the amplified signals into a plurality of corresponding high output impedance current sources; and   combining, in parallel, the high output impedance current sources to generate a summation signal;   wherein said converting uses an impedance inverter that includes at least one of:
 a first circuit comprising a series inductor and two shunt-to-ground negative inductors; 
 a second circuit comprising a shunt-to-ground inductor and two negative series inductors; 
 a third circuit comprising a series capacitor and two shunt-to-ground negative capacitors; or 
 a fourth circuit comprising a shunt-to-ground capacitor and two negative series capacitor; and 
   wherein said impedance inverter includes a lumped element equivalent component to a quarter-wavelength transmission line.   
     
     
       19. The method of claim 18, wherein said amplifying comprises applying each of the plurality of input signals to at least one active device in the corresponding input component to cause switching of the at least one active device. 
     
     
       20. The method of claim 18, further comprising providing the summation signal to an output resonator. 
     
     
       21. A switched-mode power amplifier, comprising:
 a plurality of input components, each configured to generate a low output impedance voltage source associated with a corresponding input signal;   an output resonator; and   an impedance inverter configured to provide a summation signal to the output resonator in response to the low output impedance voltage sources;   wherein the impedance inverter includes a lumped element equivalent component to a quarter-wavelength transmission line; and   wherein the impedance inverter includes at least one of:
 a first circuit comprising a series inductor and two shunt-to-ground negative inductors; 
 a second circuit comprising a shunt-to-ground inductor and two negative series inductors; 
 a third circuit comprising a series capacitor and two shunt-to-ground negative capacitors; or 
 a fourth circuit comprising a shunt-to-ground capacitor and two negative series capacitors. 
   
     
     
       22. The switched-mode power amplifier of claim 21, wherein:
 each of the plurality of input components is further configured to generate a corresponding amplified signal that constitutes a corresponding low output impedance voltage source; and   the impedance inverter is further configured to convert each of the low output impedance voltage sources into a corresponding high output impedance current source and to combine the high output impedance current sources to generate a summation signal.