Distributed circular geometry power amplifier architecture

• US 7,425,869 B2
• Filed: 06/30/2006
• Issued: 09/16/2008
• Est. Priority Date: 10/10/2000
• Status: Expired due to Term

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Hajimiri, Seyed-Ali, Aoki, Ichiro, Ruthledge, David B., Kee, Scott David
• Primary Examiner(s): Nguyen; Khanh V
• Application Number:
  US11/480,113
• Publication Number:
  US 20060250187A1
• Time in Patent Office: 809 Days
• Field of Search: 330/146, 330/262, 330/264, 330/276
• US Class Current: 330/276
• CPC Class Codes: H03F 1/223 with MOSFET's
• CPC Class Codes: H03F 2200/534 Transformer coupled at the input of an amplifier
• CPC Class Codes: H03F 2200/537 A transformer being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2200/541 Transformer coupled at the output of an amplifier
• CPC Class Codes: H03F 3/265 with field-effect transistors only
• CPC Class Codes: H03F 3/423 with MOSFET's
• CPC Class Codes: H03F 3/604 using FET's

Abstract

The present invention discloses a distributed power amplifier topology and device that efficiently and economically enhances the power output of an RF signal to be amplified. The power amplifier comprises a plurality of push-pull amplifiers interconnected in a novel circular geometry that preferably function as a first winding of an active transformer having signal inputs of adjacent amplification devices driven with an input signal of equal magnitude and opposite phase. The topology also discloses the use of a secondary winding that matches the geometry of primary winding and variations thereof that serve to efficiently combine the power of the individual power amplifiers. The novel architecture enables the design of low-cost, fully-integrated, high-power amplifiers in the RF, microwave, and millimeter-wave frequencies.

Claims

1. A power amplifier comprising:

a plurality of push-pull amplifiers, each amplifier including two gain blocks; and

wherein one of the two gain blocks of each push-pull amplifier is connected to one of the gain blocks of an adjacent push-pull amplifier so as to form a single current path through each push-pull amplifier, and wherein one or more connected terminals of the adjacent gain blocks form a virtual ac ground.

2. The power amplifier of claim 1, wherein each push-pull amplifier has a first control terminal and a second control terminal.

3. The power amplifier of claim 2 wherein the two gain blocks of each push-pull amplifier are interconnected by a primary winding segment.

4. The power amplifier of claim 1 wherein the push-pull amplifiers are controlled so as to drive alternating current around a circular current path.

5. The power amplifier of claim 2 wherein the first and second control terminals of each push-pull amplifier are adapted to receive an ac input signal of at least substantially equal magnitude and opposite phase relative to the first and second control terminals of an adjacent gain block.

6. A power amplifier comprising:

a first push-pull amplifier including a first gain block and a second gain block, each gain block having two ports, the gain blocks being interconnected at one of their two ports by a first primary winding segment; and

a second push-pull amplifier including a third gain block connected the second gain block and a fourth gain block, the third and fourth gain blocks each having two ports, the gain blocks of the second push-pull amplifier being interconnected at one of their two ports by a second primary winding segment.

7. The power amplifier of claim 6 further comprising at least one virtual ac ground.

8. The power amplifier of claim 7 wherein ac current flows from the fourth gain block flows into the first gain block.

9. The power amplifier of claim 6 wherein the push-pull amplifiers are interconnected such that, for a fundamental frequency of operation, virtual ac-grounds are presented at the plurality of ports of the gain blocks.

10. The power amplifier of claim 6 further comprising at least one additional push-pull amplifier having a pair of interconnected gain blocks, such that the fourth gain block is indirectly connected to the first gain block through the at least one additional push-pull amplifier.

11. The power amplifier of claim 6, wherein each push-pull amplifier has a first control terminal and a second control terminal.

12. The power amplifier of claim 11 wherein the first and second control terminals of each push-pull amplifier receive an ac input signal of at least substantially equal magnitude and opposite phase relative to the first and second control terminals of an adjacent push-pull amplifier.

13. A method for amplifying power, comprising:

connecting a plurality of push-pull amplifiers in series with a primary winding;

driving adjacent gain blocks of the push-pull amplifiers with input signals; and

combining the output power of the push-pull amplifiers in the primary winding using a secondary winding that is magnetically coupled to the primary winding.

14. The method of claim 13 wherein configuring the plurality of push-pull amplifiers to form the primary winding comprises combining the plurality of push-pull amplifiers to form the primary winding using at least two inductively-interconnected gain blocks.

15. The method of claim 13 wherein configuring the plurality of push-pull amplifiers to form the primary winding comprises combining the plurality of push-pull amplifiers to form the primary winding such that adjacent gain blocks of adjacent amplifiers are interconnected so as to form one or more virtual ac grounds.

16. The method of claim 13 further comprising presenting virtual ac-grounds at a port of one or more of the gain blocks for a fundamental frequency of operation.

17. The method of claim 13 wherein driving the adjacent gain blocks of the push-pull amplifiers with the input signals comprises driving one of the adjacent gain blocks of the push-pull amplifiers with ac input signal of at least substantially equal magnitude and opposite phase relative to the other of the adjacent gain blocks.

18. A power amplifier comprising:

a plurality of push-pull amplifiers, each amplifier including two gain blocks; and

wherein one of the two gain blocks of each push-pull amplifier is connected to one of the gain blocks of an adjacent push-pull amplifier so as to form a single current path through each push-pull amplifier, wherein each push-pull amplifier has a first control terminal and a second control terminal and the first and second control terminals of each push-pull amplifier are adapted to receive an ac input signal of at least substantially equal magnitude and opposite phase relative to the first and second control terminals of an adjacent gain block.

19. The power amplifier of claim 18 wherein the two gain blocks of each push-pull amplifier are interconnected by a primary winding segment.

20. The power amplifier of claim 18 wherein the push-pull amplifiers are controlled so as to drive alternating current around a circular current path.

21. The power amplifier of claim 18 wherein one or more connected terminals of the adjacent gain blocks form a virtual ac ground.