Power-shifting rf amplifiers

• US 6,747,517 B2
• Filed: 06/21/2002
• Issued: 06/08/2004
• Est. Priority Date: 12/27/2000
• Status: Active Grant

• Current Assignee: Emhiser Research Inc
• Original Assignee: Emhiser Research Inc
• Inventors: Lautzenhiser, Lloyd L., Lautzenhiser, Barry A.
• Primary Examiner(s): Choe, Henry
• Application Number:
  US10/177,572
• Publication Number:
  US 20020180532A1
• Time in Patent Office: 718 Days
• Field of Search: 330/295, 330/124.R, 330/84, 330/286, 332/103, 332/105, 375/308, 375/309
• US Class Current: 330/295
• CPC Class Codes: H03F 1/301 in MOSFET amplifiers H03F1/303, H03F1/305, H03F1/308 take precedence
• CPC Class Codes: H03F 3/601 using FET's, e.g. GaAs FET's H03F3/607, H03F3/608 take precedence

Abstract

Apparatus (70, 80, 90) and method are provided for selectively proportioning, or hot-switching, rf power to a plurality of rf outputs. The method includes: splitting a single rf signal into a plurality of split rf signals using power splitters (12, 36, 38A, 38B); separately power amplifying the split rf signals into the plurality of rf power outputs in solid-state current devices (Q1, Q2, Q3, Q4); selectively proportioning gains of the power amplifying steps; and maintaining a total rf power substantially constant during the selectively proportioning step. Preferably, the method includes series connecting the solid-state current devices (Q1, Q2, Q3, Q4) in series between a dc source-voltage (V_DC) and a lower dc voltage; and performing the separate amplifying steps in the series-connected solid-state current devices (Q1, Q2, Q3, Q4). The selective proportioning step includes adjusting gate voltages of the solid-state current devices (Q1, Q2, Q3).

Claims

1. A method for selectively proportioning rf power to a plurality of rf outputs which comprises:

a) splitting a single rf signal into a plurality of split rf signals;

b) separately power amplifying said split rf signals into said plurality of rf outputs;

c) selectively proportioning gains of said separate power amplifying steps; and

d) maintaining a summation of said gains substantially constant.

2. A method as claimed in claim 1 in which:

a) said splitting step comprises in-phase splitting; and

b) said plurality of rf outputs are in phase.

3. A method as claimed in claim 1 in which:

a) said splitting step comprises quadrature splitting; and

b) two of said rf outputs are in quadrature.

4. A method as claimed in claim 1 in which:

a) said splitting step comprises 180 degree splitting; and

b) two of said rf outputs are at 180 degrees to each other.

5. A method as claimed in claim 1 in which:

a) said selective proportioning step comprises switching all of said rf power to one of said rf outputs; and

b) said maintaining step comprises maintaining said rf power substantially constant during said switching step.

19. A method as claimed in claim 1 in which said selective proportioning of gains comprises inversely proportioning two of said gains.

20. A method as claimed in claim 1 in which said selective proportioning of gains comprises selectively proportioning said gains in response to a single, variable, power-shifting voltage.

6. A method for selectively proportioning rf power to a plurality of rf outputs which comprises:

a) series connecting a plurality of solid-state amplifying devices between a dc source-voltage and a lower dc voltage;

b) splitting an rf input signal into a plurality of split rf signals;

c) separately power amplifying said split rf signals in said series-connected solid-state amplifying devices into a plurality of rf outputs;

d) selectively proportioning gains of said separate power amplifying steps to be different, one from an other; and

e) maintaining a total rf power substantially constant during said selective proportioning step.

7. A method as claimed in claim 6 in which:

a) said splitting step comprises in-phase splitting; and

b) said plurality of rf outputs are in phase.

8. A method as claimed in claim 6 in which:

a) said splitting step comprises quadrature splitting; and

b) two of said rf outputs are in quadrature.

9. A method as claimed in claim 6 in which:

a) said splitting step comprises 180 degree splitting; and

b) two of said rf outputs are at 180 degrees to each other.

10. A method as claimed in claim 6 in which said selective proportioning step comprises switching all of said total rf power to one of said rf outputs.

11. A method as claimed in claim 6 in which:

a) said plurality of solid-state amplifying devices comprise a plurality of field-effect transistors each having a gate; and

b) said selective proportioning of gains comprises selective adjustment of a voltage to one of said gates.

12. A method as claimed in claim 6 in which said method further comprises:

a) rf decoupling an adjacent pair of said series-connected solid-state amplifying devices from each other; and

b) said rf decoupling step comprises connecting capacitors in parallel between said adjacent pair of series-connected solid-state amplifying devices and an electrical ground.

21. A method as claimed in claim 6 in which said method further comprises:

a) rf decoupling an adjacent pair of said series-connected solid-state amplifying devices from each other;

b) said rf decoupling step comprises providing a capacitance between said adjacent pair of series-connected solid-state amplifying devices and an electrical ground; and

c) said providing step comprises making an rf effective series resistance of said capacitance lower than that of any porcelain capacitor of said capacitance.

22. A method as claimed in claim 6 in which said selective proportioning of gains comprises inversely proportioning two of said gains.

23. A method as claimed in claim 6 in which said selective proportioning of gains comprises individual ones of said solid-state amplifying devices utilizing a difference in voltages between said dc source-voltage and said lower dc voltage in various selected proportions.

24. A method as claimed in claim 6 in which said selective proportioning of gains comprises selectively proportioning said gains in response to a single, variable, power-shifting voltage.

13. A method for selectively proportioning rf power to a plurality of antennas on an airplane, which method comprises:

a) splitting a single rf signal into a plurality of split rf signals;

b) separately power amplifying said split rf signals into a plurality of rf outputs;

c) separately connecting said rf power outputs to respective ones of said antennas;

d) selectively proportioning gains of said separate power amplifying steps to be different, one from another; and

e) maintaining rf power substantially constant during said selective proportioning step.

14. A method as claimed in claim 13 in which:

a) said splitting step comprises out-of-phase splitting; and

b) said method further comprises supplying said rf power to two of said antennas at different phase angles.

15. A method as claimed in claim 13 in which said selective proportioning step comprises:

a) switching said rf power from one of said antennas to the other of said antennas; and

b) maintaining said rf power substantially constant during said switching step.

16. A method as claimed in claim 13 in which said method further comprises:

a) top-mounting one of said antennas onto a fuselage of said airplane; and

b) belly-mounting the other of said antennas onto said fuselage.

25. A method as claimed in claim 13 in which:

a) said separate power amplifying steps comprise connecting a plurality of solid-state amplifying devices in series between a dc source-voltage and a lower dc voltage; and

b) said selective proportioning step comprises utilizing a difference in said dc voltages in individual ones of said solid-state amplifying devices in various percentages.

26. A method as claimed in claim 13 in which:

a) said separate power amplifying steps comprise connecting a plurality of solid-state amplifying devices in series between a dc source-voltage and a lower dc voltage;

b) said selective proportioning step comprises utilizing a difference in said dc voltages in individual ones of said solid-state amplifying devices in various percentages; and

c) said utilizing step comprises utilizing said difference in said various percentages in response to a single, variable, power-shifting voltage.

17. A method for selectively proportioning rf power among an array of antennas, which method comprises:

a) splitting a single rf signal into a plurality of split rf signals;

b) separately power amplifying said split rf signals into a plurality of rf power outputs;

c) separately connecting said rf outputs to said antennas;

d) selectively proportioning gains of said separate power amplifying steps to be different, one from an other; and

e) maintaining said rf power substantially constant during said selective proportioning step.

18. A method as claimed in claim 17 in which:

an array of antennas, which method comprises;

a) said splitting step comprises out-of-phase splitting; and

b) said separate connecting step comprises supplying said rf power outputs to two of said antennas at different phase angles.

27. A method as claimed in claim 17 in which:

a) said separate power amplifying steps comprise connecting a plurality of solid-state amplifying devices in series between a dc source-voltage and a lower dc voltage; and

b) said selective proportioning step comprises utilizing a difference in said dc voltages in individual ones of said solid-state amplifying devices in various percentages.

28. A method as claimed in claim 17 in which:

a) said separate power amplifying steps comprise connecting a plurality of solid-state amplifying devices in series between a dc source-voltage and a lower dc voltage;

b) said selective proportioning step comprises utilizing a difference in said dc voltages in individual ones of said solid-state amplifying devices in various percentages; and

c) said utilizing step comprises utilizing said difference in said various percentages in response to a single, variable, power-shifting voltage.

29. A method which comprises:

a) series connecting a plurality of solid-state amplifying devices between a dc source-voltage and a lower dc voltage;

b) separately power amplifying a plurality of rf signals in respective ones of said solid-state amplifying devices; and

c) said power amplifying step comprises utilizing any selected percentage, of a difference between said dc source-voltage and said lower dc voltage, in any selected one of said solid-state amplifying devices.

30. A method as claimed in claim 29 in which said selective utilizing step comprises controlling said different percentages in response to variations in a single, variable, power-shifting voltage.

31. A method as claimed in claim 29 in which said method further comprises:

a) rf decoupling an adjacent pair of said series-connected solid-state amplifying devices from each other; and

b) said rf decoupling step comprises connecting capacitors in parallel between said adjacent pair of series-connected solid-state amplifying devices and an electrical ground.

37. A method as claimed in claim 29 in which:

a) said method further comprises splitting a single rf signal into said plurality of rf signals prior to said separate power amplifying step;

b) said splitting step comprises in-phase splitting; and

c) two of said separately power amplified rf signals are in phase.

38. A method as claimed in claim 29 in which:

a) said method further comprises splitting a single rf signal into said plurality of rf signals prior to said separate power amplifying step;

b) said splitting step comprises quadrature splitting; and

c) two of said separately amplified rf signals are in quadrature.

39. A method as claimed in claim 29 in which:

a) said method further comprises splitting a single rf signal into said pluraiity of rf signals prior to said separate power amplifying step;

b) said splitting step comprises 180 degree splitting; and

c) two of said separately amplified rf signals are 180 degrees to each other.

40. A method as claimed in claim 29 in which said utilizing step comprises switching two of said separately amplifying rf signals to a single rf output.

41. A method as claimed in claim 29 in which:

a) said plurality of solid-state amplifying devices comprise a plurality of field-effect transistors, each having a gate; and

b) said utilizing step comprises selective adjustment of a voltage to one of said gates.

42. A method as claimed in claim 29 in which said method further comprises:

a) rf decoupling an adjacent pair of said series-connected solid-state amplifying devices from each other;

b) said rf decoupling step comprises providing a capacitance between said adjacent pair of series-connected solid-state amplifying devices and an electrical ground; and

c) said providing step comprises making an rf effective series resistance of said capacitance lower than that of any capacitor that operates at a selected operating frequency of said power amplifying step.

43. A method as claimed in claim 29 in which said utilizing step comprises inversely proportioning said selected percentages of two of said solid-state amplifying devices.

44. A method as claimed in claim 29 in which:

a) said utilizing step comprises selectively controlling gains of individual ones of said solid-state amplifying devices; and

b) said selective controlling step comprises selectively controlling said gains in response to variations in a single, variable, power-shifting voltage.

32. A method which comprises:

a) series connecting a plurality of solid-state amplifying devices between a dc source-voltage and a lower dc voltage;

b) separately power amplifying a plurality of rf signals in respective ones of said solid-state amplifying devices at a selected operating frequency;

c) said power amplifying step comprises utilizing any selected percentage, of a difference between said dc source-voltage and said lower dc voltage, in any selected one of said solid-state amplifying devices;

d) rf decoupling an adjacent pair of said series-connected solid-state amplifying devices;

e) said rf decoupling step comprises providing a capacitance between said adjacent pair of series-connected solid-state amplifying devices and an electrical ground; and

f) said providing step comprises making an rf effective series resistance of said capacitance lower than any porcelain capacitor that operates at said selected operating frequency.

33. A method as claimed in claim 32 in which said step of making said rf effective series resistance lower than any porcelain capacitor comprises paralleling capacitors.

34. A method which comprises:

a) series connecting upper and lower solid-state amplifying devices between a dc source-voltage and a lower dc voltage;

b) said series-connecting step comprises connecting a lower-voltage terminal of said upper solid-state amplifying device to an rf choke, and connecting said rf choke to a higher-voltage terminal of said lower solid-state amplifying device;

c) separately power amplifying a pair of rf signals in respective ones of said solid-state amplifying devices at a selected operating frequency;

d) said power amplifying step comprises utilizing any selected percentage, of a difference between said dc source-voltage and said lower dc voltage, in any selected one of said solid-state amplifying devices;

e) rf decoupling said solid-state amplifying devices; and

f) said rf decoupling step comprises providing a capacitance between said lower-voltage terminal and an electrical ground whose rf effective series resistance is lower than any porcelain capacitor at said selected operating frequency.

35. A method as claimed in claim 34 in which step of making said rf effective series resistance lower than any porcelain capacitor comprises paralleling capacitors.

36. A method which comprises:

a) series connecting upper and lower solid-state amplifying devices between a dc source-voltage and a lower dc voltage;

b) said series-connecting step comprises connecting a lower-voltage terminal of said upper solid-state amplifying device to an rf choke, and connecting said rf choke to a higher-voltage terminal of said lower solid-state amplifying device;

c) separately power amplifying a pair of rf signals in respective ones of said solid-state amplifying devices at a selected operating frequency; and

d) said power amplifying step comprises utilizing any selected percentage, of a difference between said dc source-voltage and said lower dc voltage, in any selected one of said solid-state amplifying devices.