Technique for wideband operation of power amplifiers

• US 6,252,461 B1
• Filed: 08/24/1998
• Issued: 06/26/2001
• Est. Priority Date: 08/25/1997
• Status: Expired due to Term

• Current Assignee: Frederick Herbert Raab
• Original Assignee: Frederick Herbert Raab
• Inventors: Raab, Frederick Herbert
• Primary Examiner(s): Shingleton, Michael B
• Application Number:
  US09/138,956
• Time in Patent Office: 1,037 Days
• Field of Search: 330/53, 330/124 R, 330/302, 330/306, 333/213, 333/214, 333/216
• US Class Current: 330/302
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/429 Two or more amplifiers or one amplifier with filters for different frequency bands are coupled in parallel at the input or output
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers
• CPC Class Codes: H03H 7/48 Networks for connecting several sources or loads, working on the same frequency or frequency band, to a common load or source phase shifters providing two or more output signals H03H7/21

Abstract

A method and a circuit for power amplification over a wide frequency range based upon the use of minimum-rating filters or matching networks, negative-component signal processing, and single or multiple amplifiers. The filters and matching networks are preferably designed to minimize the required ratings of the amplifier(s) driving them. The signal processor or generator preferably uses negative components to produces a driving signal that is compensated for the ripple in the filter, matching network, and load. The outputs of multiple amplifiers optimized for different frequency ranges can be combined into a single load with flat frequency response, resistive loads presented to the amplifiers, and no inherent power loss in the combining network.

Claims

1. A signal-processing method for transforming an input signal to a desired output signal, said method comprising the steps of:

(a) selecting a network topology;

(b) selecting a set of components, at least one of said components being a simulated negative component selected from negative resistors, negative capacitors, and negative inductors;

(c) assigning predetermined initial-values to the resistance, capacitance, and inductance of each of said selected components, said predetermined initial values including a negative value for at least one said simulated negative component;

(d) varying the values of said selected set from said predetermined initial values until said desired output signal is obtained;

(e) fixing the values of said selected set at the resultant values; and

(f) converting component values into parameters required for signal processing.

2. A signal-processing device operable by the method recited in claim 1.

3. A device as recited in claim 2 wherein the signal-processing device comprises a programmable signal source.

4. A device as recited in claim 2 wherein the signal-processing device comprises one or more analog circuits.

5. A device as recited in claim 2 wherein the signal-processing device comprises a digital signal processor.

6. A signal-processing device as recited in claim 2, further comprising a second input for load characteristics and means to change said values of said components in response to the load characteristics.

7. A system for amplifying a signal and delivering an amplified signal to a load, the system having an input and output and comprising:

(a) a negative-component signal processor,

(b) an amplifier, and

(c) an output network;

the system being organized so that;

(i) the input of the system is coupled to the input of the negative-component signal processor,

(ii) the output of the negative-component signal processor is coupled to the amplifier,

(iii) the output of the amplifier is coupled to the output network,

(iv) the output of the output network is coupled to the system output, and

(v) the system output is in turn coupled to the load;

the negative-component signal processor comprising one or more simulated networks with topologies corresponding to the output network and load and having one or more simulated negative components;

whereby the amplified signal is delivered to the load with a substantially flat frequency response.

8. A system as recited in claim 7 wherein the negative-component signal processor comprises first and second subprocessors and is organized so that:

(a) the input of the negative-component signal processor is coupled to the input of the first subprocessor and the output of the first subprocessor is coupled to the input of the second subprocessor and to the output of the negative-component signal processor,

(b) the second subprocessor corresponds to the topology of the output network and load with values corresponding to the values of the components in the output network and load,

(c) the first subprocessor corresponds to a mirror image of the reactive components in the second subprocessor with negative values of the reactive components.

9. A system as recited in claim 7 wherein the signal-processing device comprises a programmable signal source.

10. A system as recited in claim 7 wherein the signal-processing device comprises one or more analog circuits.

11. A system as recited in claim 7 wherein the signal-processing device comprises a digital signal processor.

12. A system as recited in claim 7 wherein the output network comprises a minimum-rating network.

13. A system as recited in claim 7 wherein the output network comprises a filter.

14. A system as recited in claim 7 wherein the output network comprises a matching network.

15. A system as recited in claim 7 wherein the output network comprises a broadbanding network.

16. A network as recited in claim 7, further comprising a load-sensing means for measuring load characteristics and means for varying values of the components of the output network in response to said load characteristics, whereby the rating, impedance, and attenuation characteristics of the network are maintained.

17. A network as recited in claim 7, further comprising a load-sensing means for measuring load characteristics and means for varying values of the components of the negative-component signal processor in response to said load characteristics, whereby the substantially flat frequency response of the system is maintained.

18. A network as recited in claim 7, further comprising

(a) a load-sensing means for measuring load characteristics and means for varying values of the components of the output network in response to said load characteristics and

(b) a means for varying values of the components of the negative-component signal processor in response to said load characteristics,

whereby rating, impedance, and attenuation characteristics of the network and a substantially flat frequency response of the system are maintained.

19. A system as recited in claim 7, wherein the output of the negative-component signal processor includes modulation waveforms.

20. A system as in recited in claim 7 wherein the amplifier is of a type employing an envelope-elimination-and-restoration technique.

21. A system for amplifying a signal and delivering an amplified signal to a load, the system having an input and output and comprising:

(a) a negative-component signal processor,

(b) an amplifier, and

(c) an output network,

the system being organized so that;

(i) the input of the system is coupled to the input of the negative-component signal processor,

(ii) the output of the negative-component signal processor is coupled to the amplifier,

(iii) the output of the amplifier is coupled to the output network,

(iv) the output of the output network is coupled to the system output, and

(v) the system output is in turn coupled to the load;

the negative-component signal processor comprising one or more simulated networks with topologies corresponding to the output network and load and having one or more simulated negative components;

the load network including a load-sensing means for measuring load characteristics and the system including means for varying values of the components in the negative-component signal processor in response to said load characteristics;

whereby the amplified signal is delivered to the load with a substantially flat frequency response.

22. A system as recited in claim 21 wherein the negative-component signal processor comprises first and second subprocessors and is organized so that:

(a) the input of the negative-component signal processor is coupled to the input of the first subprocessor and the output of the first subprocessor is coupled to the input of the second subprocessor and to the output of the negative-component signal processor,

(b) the second subprocessor corresponds to the topology of the output network and load with values corresponding to the values of the components in the output network and load,

(c) the first subprocessor corresponds to a mirror image of the reactive components in the second subprocessor with negative values of the reactive components.

23. A system as recited in claim 21 wherein the load sensor comprises a directional coupler.

24. A system as recited in claim 21 wherein the load sensor comprises an SWR bridge.

25. A system as recited in claim 21 wherein the load sensor comprises apparatus for measuring load voltage and current.

26. A system as recited in claim 21 wherein the output network is of the minimum-rating type.

27. A system as recited in claim 21, further comprising a means for varying values of the components of the output network in response to said load characteristics, whereby the rating, impedance, and attenuation characteristics of the network are maintained.

28. A system for amplifying a signal and delivering an amplified signal to a load, the system having an input and output and comprising:

(a) a negative-component signal processor,

(b) multiple amplifiers, and

(c) multiple output networks;

said system being organized so that;

(i) the system input is coupled to a negative-component signal processor,

(ii) the outputs of the negative-component signal processor are coupled to the amplifiers,

(iii) the amplifier outputs are coupled to output networks,

(iv) the outputs of the output networks are coupled to the system output, and

(v) the system output is coupled to the load;

the negative-component signal processor comprising one or more simulated networks with topologies corresponding to the output networks and load and having one or more simulated negative components;

whereby amplification is accomplished over a wide frequency band with a substantially flat frequency response.

29. A system as recited in claim 28 wherein the negative-component signal processor comprises multiple subprocessors organized so that:

(a) the input of the negative-component signal processor is coupled to each of the subprocessors,

(b) the output of each subprocessor is coupled to an amplifier,

(c) the topology of each subprocessor corresponds to a mirror image of the output network and load that are coupled to the amplifier that is driven by the subprocessor,

(d) the values of the reactive components in the subprocessor are the negatives of the values of the reactive components in the output network and load that are coupled to the amplifier that is driven by the subprocessor.

30. A system as recited in claim 28 having one or more pairs of amplifiers and one or more pairs of output filters, both filters in each pair having substantially the same cut-off frequency, one filter being a low-pass type and the other being a high-pass type.

31. A system as recited in claim 28 wherein the filters are of the Butterworth type.

32. A system as recited in claim 28 wherein the filters are of the minimum-rating type.

33. A system as recited in claim 28 in which the network outputs are coupled in parallel to the load.

34. A system as recited in claim 28 in which the network outputs are coupled in series to the load.

35. A network as recited in claim 28, further comprising one or more load-sensing means for measuring load characteristics and one or more means for varying values of the components of the output network in response to said load characteristics, whereby the rating, impedance, and attenuation characteristics of the network are maintained.

36. A network as recited in claim 28, further comprising one or more load-sensing means for measuring load characteristics and one or more means for varying values of the components of the negative-component signal processor in response to said load characteristics, whereby the substantially flat frequency response of the system is maintained.

37. A network as recited in claim 28, further comprising

(a) one or more load-sensing means for measuring load characteristics and one or more means for varying values of the components of the output network in response to said load characteristics and

(b) one or more means for varying values of the components of the negative-component signal processor in response to said load characteristics;

whereby rating, impedance, and attenuation characteristics of the network and the substantially flat frequency response of the system are maintained.

38. A system as recited in claim 28 wherein the signal-processing device comprises a programmable signal source.

39. A system as recited in claim 28 wherein the signal-processing device comprises one or more analog circuits.

40. A system as recited in claim 28 wherein the signal-processing device comprises a digital signal processor.

41. A system as recited in claim 28 wherein the negative-component signal processor produces modulation waveforms.

42. A system as recited in claim 28, further comprising three or more amplifiers and output networks, all outputs of the output networks being coupled in parallel to the load.

43. A system as recited in claim 28, further comprising three or more amplifiers and output networks, outputs of the output networks being coupled to the load through pairs of low-pass and high-pass filters.

44. A system for delivering a signal to a load, said system having a system input and a system output, said system comprising:

(a) at least one negative-component signal processor having signal-processor inputs and signal-processor outputs, and

(b) at least one output network having output-network inputs and output-network outputs;

the system being organized so that;

(i) the system input is coupled to the signal-processor inputs of the negative-component signal processors,

(ii) the signal-processor outputs of the negative-component signal processors are coupled to the output-network inputs,

(iii) the output-network outputs are coupled to the system output, and

(iv) the system output is in turn coupled to the load;

said at least one negative-component signal processor comprising one or more simulated networks with topologies corresponding to the output networks and load and having one or more simulated negative components;

whereby the signal is delivered to the load with a substantially flat frequency response.

45. A system for delivering a signal to a load, said system having a system input and a system output, said system comprising:

(a) at least one negative-component signal processor having signal-processor inputs and signal-processor outputs, and

(b) at least one output network having output-network inputs, output-network outputs, and an output-network frequency response;

the system being organized so that;

(i) the system input is coupled to the signal-processor inputs of the negative-component signal processors,

(ii) the signal-processor outputs of the negative-component signal processors are coupled to the output network inputs,

(iii) the output-network outputs are coupled to the system output, and

(iv) the system output is in turn coupled to the load;

said at least one negative-component signal processor comprising one or more simulated networks with topologies corresponding to the output network and load and having a signal-processor frequency response opposite to said output network frequency response;

whereby the signal is delivered to the load with a substantially flat frequency response.

46. A system for delivering a signal to a load, the system having a system input and a system output, said system comprising:

(a) one negative-component signal processor having a signal-processor input and signal-processor output, and

(b) one output network having an output-network input and an output-network output;

the system being organized so that;

(i) the system input is coupled to the signal-processor input of the negative-component signal processor,

(ii) the signal-processor output of the negative-component signal processor is coupled to the output-network input,

(iii) the output-network output is coupled to the system output, and

(iv) the system output is in turn coupled to the load;

said one negative-component signal processor comprising one or more simulated networks with topologies corresponding to the output network and load and having one or more simulated negative components;

whereby the signal is delivered to the load with a substantially flat frequency response.

47. A system for amplifying a signal and delivering an amplified signal to a load, the system having a system input and a system output, said system comprising:

(a) at least one negative-component signal processor having signal-processor inputs and signal-processor outputs,

(b) at least one output network having output-network inputs and output-network outputs

(c) a load sensor having a load-sensor output;

the system being organized so that;

(i) the system input is coupled to the signal-processor inputs of the negative-component signal processors,

(ii) the signal-processor outputs of the negative-component signal processors are coupled to the output-network inputs,

(iii) the output-network outputs are coupled to the system output,

(iv) the system output is in turn coupled to the load, and

(v) the load-sensor output of the load sensor is coupled to a signal-processor input of the negative-component signal processor;

said at least one negative-component signal processor comprising one or more simulated networks with topologies corresponding to the output network and load and having one or more simulated negative components;

said load sensor having the capability to measure load characteristics and said system including means for varying values of the components in the negative-component signal processor in response to said load characteristics;

whereby the signal is delivered to the load with a substantially flat frequency response.

48. A system for delivering a signal to a load, the system having a system input and a system output, said system comprising:

(a) at least one negative-component signal processor having signal-processor inputs and signal-processor outputs, and

(b) a multitude of output networks, each having an output-network input and an output-network outputs;

the system being organized so that;

(i) the system input is coupled to the signal-processor inputs of the negative-component signal processors,

(ii) the signal-processor outputs of the negative-component signal processors are coupled to the output-network inputs,

(iii) the output-network outputs are coupled to the system output, and

(iv) the system output is in turn coupled to the load;

said at least one negative-component signal processor comprising one or more simulated networks with topologies corresponding to the output networks and load and having one or more simulated negative components;

whereby the signal is delivered to the load with a substantially flat frequency response.