Variable phase-shifting rf power amplifiers

• US 6,690,238 B2
• Filed: 03/04/2002
• Issued: 02/10/2004
• 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:
  US10/091,056
• Publication Number:
  US 20020118066A1
• Time in Patent Office: 708 Days
• Field of Search: 330/295, 330/286, 330/124.R, 375/308, 375/309, 332/103, 332/105
• 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

Variable phase-shifting rf power amplifiers (10, 30, 50) shift rf outputs at any angle up to 90, 180, or 270 degrees, respectively, while maintaining an rf output substantially constant. The variable phase-shifting rf power amplifiers (10, 30, 50) include two to four field-effect transistors (Q1, Q2, Q3, Q4) that are interposed between phase splitters and combiners, and that are connected in series between a source voltage and a lower voltage. Phase shifting is achieved by selectively and variably controlling amplification of the field-effect transistors (Q1, Q2, Q3, Q4). Selective and variable control of amplification is achieved by separately and variably controlling gate voltages of the field-effect transistors (Q1, Q2, Q3, Q4), whereby a difference between the source voltage and the lower voltage is used selectively by one of the field-effect transistors (Q1, Q2, Q3, Q4) and selectively proportioned between two of the field-effect transistors (Q1, Q2, Q3, Q4). Phase controls (34, 54) generate separate and variable phase-shifting voltages, or gate voltages, in response to a variable phase-shifting voltage.

Claims

1. A method for phase-shifting an rf output which comprises:

a) phase-splitting an rf input into a plurality of rf signals that are at different phase angles;

b) amplifying a selected one of said rf signals;

c) simultaneously amplifying an other of said rf signals;

d) inversely controlling gains of said amplifying steps; and

e) combining said rf signals into said rf output subsequent to said amplifying steps.

2. A method as claimed in claim 1 in which said inversely controlling step comprises variably biasing a solid-state amplifying device.

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

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

b) said inversely controlling step comprises utilizing a difference in said voltages in inverse percentages in said solid-state amplifying devices.

8. A method as claimed in claim 1 in which said inverse controlling of said gains comprises inversely controlling said gains as a function of a single, variable, phase-control voltage.

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

a) said amplifying steps comprise connecting a lower-voltage terminal of a first solid-state amplifying device to an rf choke, and connecting said rf choke to a higher-voltage terminal of a second solid-state amplifying device; and

b) said inversely controlling step comprises maintaining a voltage difference substantially constant between a higher-voltage terminal of said first solid-state amplifying device and a lower-voltage terminal of said second solid-state amplifying device, irrespective of said inverse controlling step.

10. A method as claimed in claim 1 in which said method further comprises maintaining said rf output substantially constant irrespective of said inverse controlling of said gains.

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

a) said amplifying steps comprise connecting a lower-voltage terminal of a first solid-state amplifying device to an rf choke, and connecting said rf choke to a higher-voltage terminal of a second solid-state amplifying device; and

b) said inversely controlling step comprises utilizing a voltage difference between a higher-voltage terminal of said first solid-state amplifying device and a lower-voltage terminal of said second solid-state amplifying device in selected percentages.

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

a) said inverse controlling of said gains comprises inversely controlling said gains as a function of a single, variable, phase-control voltage; and

b) said phase-shifting of said rf output comprises phase-shifting said rf output to angles that are a substantially linear function of said single, variable, phase-control voltage.

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

a) said amplifying steps comprise connecting a lower-voltage terminal of a first solid-state amplifying device to an rf choke, and connecting said rf choke to a higher-voltage terminal of a second solid-state amplifying device;

b) said inversely controlling step comprises utilizing a voltage difference between a higher-voltage terminal of said first solid-state amplifying device and a lower-voltage terminal of said second solid-state amplifying device in selected percentages;

c) said utilizing step comprises variably biasing one of said solid-state amplifying devices; and

d) said phase-shifting of said rf output comprises phase-shifting said rf output to angles that are a substantially linear function of voltage variations of said variable biasing step.

4. A method for phase-shifting an rf output which comprises:

a) splitting an rf input into first and second rf signals that are at different phase angles;

b) inputting said first rf signal into a first solid-state amplifying device;

c) inputting said second rf signal into a second solid-state amplifying device;

d) amplifying said first and second rf signals with selective and individually different gains; and

e) combining said rf signals subsequent to said amplifying step.

5. A method as claimed in claim 4 in which said step of amplifying with selective and different gains comprises selectively biasing one of said solid-state amplifying devices.

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

a) said method further comprises connecting said solid-state amplifying devices in series between a dc source voltage and a lower voltage; and

b) said step of amplifying with selective and different gains comprises proportionally dividing a difference between said voltages in said solid-state amplifying devices.

7. A method for binary-phase-shift-key modulating which comprises:

a) splitting an rf output into 0, 90, and 180 degree rf signals;

b) separately amplifying said rf signals to be different, one from an other;

c) combining said separately amplified rf signals into a single rf output;

d) phase shifting said single rf output as a function of said separately-amplified rf signals; and

e) preventing said single rf output from decreasing to 0 degrees when said rf output is phase-shifted 180 degrees.

14. A method as claimed in claim 7 in which said preventing step further comprises maintaining said rf output substantially constant irrespective of said 180 degree phase-shifting.

15. A method as claimed in claim 7 in which said method further comprises accomplishing said 180 degree phase-shifting step in response to a single phase-control voltage.

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

a) said method further comprises accomplishing said 180 degree phase-shifting step in response to a single phase-control voltage; and

b) said method still further comprises making said phase-shifting substantially linear to changes in said single phase-control voltage.

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

a) said method further comprises accomplishing said 180 degree phase-shifting step in response to a single phase-control voltage;

b) said method still further comprises making said phase-shifting substantially linear to changes in said single phase-control voltage; and

c) said method still further comprises maintaining said rf output substantially constant irrespective of said 180 degree phase-shifting.

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

a) said separate amplifying steps comprise connecting three solid-state amplifying devices in dc series;

b) said binary-phase-shift-key modulating comprises utilizing a dc voltage in selected percentages in said solid-state amplifying devices; and

c) said method still further comprises maintaining said rf output substantially constant irrespective of said selected percentages.

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

a) said amplifying steps comprise connecting three solid-state amplifying devices in dc series;

b) said separate amplifying steps further comprise utilizing a dc voltage in selected percentages in said solid-state amplifying devices;

c) said utilizing step comprises variably biasing two of said solid-state amplifying devices;

d) said variable biasing step comprises using a single phase-control voltage; and

e) said variable biasing step comprises making a phase angle change of said rf output substantially linear with said single phase-control voltage.

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

a) said separate amplifying steps comprise connecting a plurality of solid-state amplifying devices in dc series;

b) said binary-phase-shift-key modulating comprises utilizing a difference in a dc voltage in selected percentages in various ones of said solid-state amplifying devices; and

c) said utilizing step comprises making a phase angle of said rf output a substantially linear function of a single phase-control voltage.

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

a) said separate amplifying steps comprise connecting a plurality of solid-state amplifying devices in dc series;

b) said binary-phase-shift-key modulating comprises utilizing a difference in a dc voltage in selected percentages in various ones of said solid-state amplifying devices;

c) said utilizing step comprises making a phase angle of said rf output a substantially linear function of a single phase-control voltage; and

d) said method still further comprises maintaining said rf output substantially constant irrespective of said selected percentages.

22. A method which comprises:

a) phase-splitting an rf input into a plurality of rf signals whose phase angles encompass first and second phase angles;

b) separately and simultaneously amplifying said rf signals;

c) selectively proportioning gains of said amplifying steps to be different, one from an other;

d) combining said separately and simultaneously amplified rf signals into a single rf output; and

e) phase-shifting said rf output to selected phase angles between said first and second phase angles as a function of said selective proportioning step.

23. A method as claimed in claim 22 in which said selective proportioning step comprises controlling one of said gains as a function of a variable phase-control voltage.

24. A method as claimed in claim 22 in which said selective proportioning step comprises controlling said gains as different functions of a single, variable, phase-control voltage.

25. A method as claimed in claim 22 in which said method further comprises maintaining said rf output of said combining step substantially constant.

26. A method as claimed in claim 22 in which:

a) said method further comprises maintaining said rf output of said combining step substantially constant;

b) said maintaining step comprises said selective proportioning of said gains; and

c) said selective proportioning of said gains comprises making one of said gains a function of a variable phase-control voltage.

27. A method as claimed in claim 22 in which:

a) said method further comprises maintaining said rf output of said combining step substantially constant;

b) said maintaining step comprises said selective proportioning of said gains; and

c) said selective proportioning of said gains comprises making both of said gains a function of a single, variable, phase-control voltage.

28. A method as claimed in claim 22 in which said separate amplifying steps comprise connecting a plurality of solid-state amplifying devices in dc series.

29. A method as claimed in claim 22 in which:

a) said separate amplifying steps comprise connecting a plurality of solid-state amplifying devices in dc series; and

b) said phase-shifting step comprises utilizing a difference in a dc voltage in selected percentages in various ones of said solid-state amplifying devices.

30. A method as claimed in claim 22 in which:

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

b) said phase-shifting step comprises utilizing a difference in said voltages in selected percentages in various ones of said solid-state amplifying devices; and

c) said utilizing step comprises controlling a gain of one of said solid-state amplifying devices as a function of a variable phase-control voltage.

31. A method as claimed in claim 22 in which:

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

b) said phase-shifting step comprises utilizing a difference in said voltages in selected percentages in various ones of said solid-state amplifying devices; and

c) said utilizing step comprises controlling gains of all of said solid-state amplifying devices as a function of a single, variable, phase-control voltage.

32. A method as claimed in claim 22 in which:

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

b) said phase-shifting step comprises utilizing a difference in said voltages in selected percentages in various ones of said solid-state amplifying devices;

c) said utilizing step comprises controlling gains of all of said solid-state amplifying devices as a function of a single, variable, phase-control voltage; and

d) said method further comprises phase-shifting said rf output as a substantially linear function of said single, variable, phase-control voltage.

33. A method as claimed in claim 22 in which:

a) said separate amplifying steps comprise connecting a plurality of solid-state amplifying devices in dc series; and

b) said method further comprises phase-shifting said rf output as a substantially linear function of a single, variable, phase-control voltage.

34. A method as claimed in claim 22 in which:

a) said separate amplifying steps comprise connecting a plurality of solid-state amplifying devices in dc series; and

b) said method further comprises maintaining said rf output substantially constant irrespective of said phase-shifting step.

35. A method as claimed in claim 22 in which:

a) said separate amplifying steps comprise connecting a plurality of solid-state amplifying devices in dc series;

b) said method further comprises phase-shifting said rf output as a substantially linear function of a single, variable, phase-control voltage; and

c) said method further comprises maintaining said rf output substantially constant irrespective of said phase-shifting step.