System and method for noise and spurious suppression in power amplifier systems

• US 6,791,408 B2
• Filed: 06/20/2002
• Issued: 09/14/2004
• Est. Priority Date: 07/05/2000
• Status: Expired due to Term

• Current Assignee: Teledyne Defense Electronics LLC (Teledyne Technologies Incorporated)
• Original Assignee: Teledyne Technologies Incorporated
• Inventors: Jensen, Charles E., Goren, Yehuda G., Lally, Philip M., Gagne, Donald R., Zavadil, David
• Primary Examiner(s): Mottola, Steven J.
• Application Number:
  US10/176,296
• Publication Number:
  US 20020196077A1
• Time in Patent Office: 817 Days
• Field of Search: 330/43, 330/136, 330/144, 330/149, 330/151
• US Class Current: 330/149
• CPC Class Codes: H03F 2200/372 Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 3/56 using klystrons

Abstract

An amplifier system is disclosed. The amplifier system includes a first amplifier, a second amplifier, and a phase noise suppression circuit. The first amplifier includes an input signal terminal and an output signal terminal. The second amplifier includes an input signal terminal and an output signal terminal. The input signal terminal of the second amplifier is coupled to the output signal terminal of the first amplifier. The phase noise suppression circuit includes first and second input terminals and an output terminal. The first input terminal of the phase noise suppression circuit is coupled to the input signal terminal of the first amplifier. The second input terminal of the phase noise suppression circuit is coupled to the output signal terminal of the second amplifier. The output terminal of the phase noise suppression circuit is coupled to the first amplifier.

Claims

1. An amplifier system, comprising:

a first amplifier having an input signal terminal and an output signal terminal;

a second amplifier having an input signal terminal and an output signal terminal, wherein the input signal terminal is coupled to the output signal terminal of the first amplifier; and

a phase noise suppression circuit having first and second input terminals and an output terminal, wherein the first input terminal is coupled to the input signal terminal of the first amplifier, the second input terminal is coupled to the output signal terminal of the second amplifier, and the output terminal is coupled to the first amplifier; and

a supplemental noise suppression circuit having first and second input terminals, wherein the first terminal is coupled to the input signal terminal of the first amplifier and the second input terminal is coupled to the output signal terminal of the second amplifier.

2. The amplifier system of claim 1, further comprising an amplitude noise suppression circuit having first and second input terminals and an output terminal, wherein the first input terminal is coupled to the input signal terminal of the first amplifier, the second input terminal is coupled to the output signal terminal of the second amplifier, and the output terminal is coupled to the first amplifier.

3. The amplifier system of claim 1, wherein the supplemental noise suppression circuit includes a circuit selected from the group consisting of a feedforward noise suppression circuit and a feedback noise suppression circuit.

4. The amplifier system of claim 1, wherein:

the first amplifier includes a solid state transistor; and

the output terminal of the phase noise suppression circuit is coupled to an output terminal of the solid state transistor.

5. The amplifier system of claim 4, further comprising an amplitude noise suppression circuit having first and second input terminals and an output terminal, wherein the first input terminal is coupled to the input signal terminal of the first amplifier, the second input terminal is coupled to the output signal terminal of the second amplifier, and the output terminal is coupled to an input terminal of the solid state transistor.

6. The amplifier system of claim 4, wherein:

the solid state transistor includes a field effect transistor; and

the output terminal of the phase noise suppression circuit is coupled to a drain terminal of the field effect transistor.

7. The amplifier system of claim 6, further comprising an amplitude noise suppression circuit having first and second input terminals and an output terminal, wherein the first input terminal is coupled to the input signal terminal of the first amplifier, the second input terminal is coupled to the output signal terminal of the second amplifier, and the output terminal is coupled to a gate terminal of the field effect transistor.

8. The amplifier system of claim 1, wherein:

the first amplifier includes a vacuum tube amplifier; and

the output terminal of the of the phase noise suppression circuit is coupled to one of an electron source of the vacuum tube amplifier and an interaction region of the vacuum tube amplifier.

9. The amplifier system of claim 8, further comprising an amplitude noise suppression circuit having a first and second input terminals and an output terminal, wherein the first input terminal is coupled to the input signal terminal of the vacuum tube amplifier, the second input terminal is coupled to the output signal terminal of the second amplifier, and the output terminal is coupled to one of a focusing electrode of the electron source of the vacuum tube amplifier and a grid of the electron source of the vacuum tube amplifier.

10. An amplifier system, comprising:

a first amplifier having an input signal terminal and an output signal terminal, wherein the first amplifier includes a solid state transistor;

a second amplifier having an input signal terminal and an output signal terminal, wherein the input signal terminal is coupled to the output signal terminal of the first amplifier; and

an amplitude noise suppression circuit having first and second input terminals and an output terminal, wherein the first input terminal is coupled to the input signal terminal of the first amplifier, the second input terminal is coupled to the output signal terminal of the second amplifier, and the output terminal of the amplitude noise suppression circuit is coupled to an input terminal of the solid state transistor.

11. The amplifier system of claim 10, further comprising a supplemental noise suppression circuit having first and second input terminals, wherein the first input terminal is coupled to the input signal terminal of the first amplifier and the second input terminal is coupled to the output signal terminal of the second amplifier.

12. The amplifier system of claim 11, wherein the supplemental noise suppression circuit includes a circuit selected from the group consisting of a feedforward noise suppression circuit and a feedback noise suppression circuit.

13. The amplifier system of claim 10, wherein:

the solid state transistor includes a field effect transistor; and

the output terminal of the amplitude noise suppression circuit is coupled to a gate terminal of the field effect transistor.

14. A method for suppressing noise in an amplifier introduced by cascaded first and second amplifiers, comprising:

detecting a phase difference between an input signal to the first amplifier and an output signal from the second amplifier indicative of phase noise introduced by the first and second amplifiers; and

modulating a voltage at a terminal of the first amplifier based on the detected phase difference, wherein the first amplifier includes a solid state transistor, and wherein modulating a voltage includes modulating a voltage at an output terminal of the solid state transistor.

15. The method of claim 14, further comprising:

detecting an amplitude difference between the input signal to the first amplifier and an output signal from the second amplifier indicative of amplitude noise introduced by the first and second amplifier; and

modulating a voltage at a second terminal of the first amplifier based on the detected amplitude difference.

16. The method of claim 14, further comprising:

detecting an amplitude difference between the input signal to the first amplifier and an output signal from the second amplifier indicative of amplitude noise introduced by the first and second amplifier; and

modulating a voltage at an input terminal of the solid state transistor based on the detected amplitude difference.

17. A method for suppressing noise in an amplifier introduced by cascaded first and second amplifiers, comprising:

detecting an amplitude difference between the input signal to the first amplifier and an output signal from the second amplifier indicative of amplitude noise introduced by the first and second amplifier; and

modulating a voltage at a terminal of the first amplifier based on the detected amplitude difference, wherein the first amplifier includes a solid state transistor, and wherein modulating a voltage includes modulating a voltage at an input terminal of the solid state transistor.