Coupled coils inter-stage matching network

Patent metadata

Field	Value
Publication number	US-9787256-B1
Application number	US-201615184738-A
Country	US
Kind code	B1
Filing date	Jun 16, 2016
Priority date	Jun 16, 2016
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

An amplifier circuit having an improved inter-stage matching network and improved performance. In one embodiment, an RF signal source having an output impedance Z SOURCE is approximately impedance matched through an inductive tuning circuit to a power amplifier having an input impedance Z PA . The inductive tuning circuit includes a tunable capacitor element C 1 and inductive elements L 1 , L 2 , which may be fabricated as stacked conductor coils. Since the capacitance of C 1 is tunable, impedance matching is available over a broad range of RF frequencies. Also provided are DC isolation between the RF signal source and the power amplifier, coupling of a voltage source to the output of the RF signal source through L 1 , and coupling of a bias voltage to the input of the power amplifier through L 2.

First claim

What is claimed is:

1. A radio frequency (RF) amplifier circuit, including:
(a) a power amplifier having an input with impedance Z PA ;
(b) an inductively coupled tuning circuit including first and second inductive elements having a mutual inductance and each having a first terminal and a second terminal, and a tunable capacitor element coupled to the first terminal of the first inductive element and configured to be coupled to circuit ground, wherein:
(1) a node between the first terminal of the first inductive element and the tunable capacitor element is configured to be coupled to an RF signal source having an output with impedance Z SOURCE ;
(2) the second terminal of the first inductive element is configured to be coupled to a first DC voltage source;
(3) the first terminal of the second inductive element is coupled to the input of the power amplifier; and
(4) the second terminal of the second inductive element is configured to be coupled to a second DC voltage source;

wherein the output of the RF signal source is inductively coupled to the input of the power amplifier and the inductive tuning circuit is tunable to approximately impedance match Z SOURCE to Z PA over a selected range of RF frequencies.

2. A radio frequency (RF) amplifier circuit, including:
(a) an inductively coupled tuning circuit including first and second inductive elements having a mutual inductance and each having a first terminal and a second terminal, and a tunable capacitor element coupled to the first terminal of the first inductive element and configured to be coupled to circuit ground;
(b) an RF signal source having an output with impedance Z SOURCE , the output being coupled between the first terminal of the first inductive element and the tunable capacitor element;
(c) a power amplifier having an input with impedance Z PA , the input being coupled to the first terminal of the second inductive element;
(d) a first DC voltage source coupled to the second terminal of the first inductive element; and
(e) a second DC voltage source coupled to the second terminal of the second inductive element;
wherein the output of the RF signal source is inductively coupled to the input of the power amplifier and the inductive tuning circuit is configured to approximately impedance match Z SOURCE to Z PA over a selected range of RF frequencies.

3. A radio frequency (RF) amplifier circuit, including:
(a) an inductively coupled tuning circuit including first and second stacked inductive coils having mutual inductance and each having a first terminal and a second terminal, and a digitally tunable capacitor element coupled to the first terminal of the first inductive element and configured to be coupled to circuit ground;
(b) a driver circuit having an output with impedance Z SOURCE , the output being coupled between the first terminal of the first inductive element and the tunable capacitor element;
(c) a power amplifier having an input with impedance Z PA , the input being coupled to the first terminal of the second inductive element;
(d) a first DC voltage source coupled to the second terminal of the first inductive element; and
(e) a second DC voltage source coupled to the second terminal of the second inductive element;
wherein the output of the driver circuit is inductively coupled to the input of the power amplifier and the inductively coupled tuning circuit is configured to approximately impedance match Z SOURCE to Z PA over a selected range of RF frequencies.

4. The invention of claim 1 or 2 , wherein the first and second inductive elements are fabricated on an integrated circuit as stacked inductive coils.

5. The invention of claim 1 or 2 , wherein the RF signal source is a driver circuit.

6. The invention of claim 1 or 2 , wherein the tunable capacitor element is a digitally tunable capacitor.

7. The invention of claim 1 , 2 , or 3 , further including a first bypass capacitor coupled to the second terminal of the first inductive element.

8. The invention of claim 1 , 2 , or 3 , further including a second bypass capacitor coupled to the second terminal of the second inductive element.

9. The invention of claim 1 , 2 , or 3 , wherein the RF amplifier circuit is fabricated as an integrated circuit.

10. The invention of claim 9 , wherein the integrated circuit is fabricated on a high Q substrate.

11. The invention of claim 9 , wherein the integrated circuit is fabricated on a silicon-insulator (SOI) substrate using complementary metal oxide semiconductor (CMOS) technology.

12. A method of impedance matching a radio frequency (RF) source signal having an output with impedance Z SOURCE to a power amplifier input having an input with impedance Z PA , including:
(a) inductively coupling the output of the RF source signal to the input of the power amplifier through an inductive tuning circuit including first and second inductive elements having a mutual inductance, and a tunable capacitor element coupled to the first inductive element and configured to be coupled to circuit ground;
(b) providing a first DC voltage to the output of the RF source signal through the first inductive element;
(c) providing a second DC voltage to the input of the power amplifier through the second inductive element; and
(d) tuning the inductive tuning circuit to approximately impedance match Z SOURCE to Z PA over a selected range of RF frequencies.

13. A method of impedance matching a radio frequency (RF) source signal to a power amplifier input in an amplifier circuit, including:
(a) providing a power amplifier having an input with impedance Z PA ;
(b) providing an inductively coupled tuning circuit including first and second inductive elements having a mutual inductance and each having a first terminal and a second terminal, and a tunable capacitor element coupled to the first terminal of the first inductive element and configured to be coupled to circuit ground, wherein:
(1) a node between the first terminal of the first inductive element and the tunable capacitor element is configured to be coupled to an RF signal source having an output with impedance Z SOURCE ;
(2) the second terminal of the first inductive element is configured to be coupled to a first DC voltage source;
(3) the first terminal of the second inductive element is coupled to the input of the power amplifier; and
(4) the second terminal of the second inductive element is configured to be coupled to a second DC voltage source;

(c) inductively coupling the output of the RF signal source to the input of the power amplifier; and
(d) tuning the inductive tuning circuit to approximately impedance match Z SOURCE to Z PA over a selected range of RF frequencies.

14. A method of impedance matching a radio frequency (RF) source signal to a power amplifier input in an amplifier circuit, including:
(a) providing an inductive tuning circuit including first and second inductive elements having a mutual inductance and each having a first terminal and a second terminal, and a tunable capacitor element coupled to the first terminal of the first inductive element and configured to be coupled to circuit ground;
(b) providing an RF signal source having an output with impedance Z SOURCE , the output being coupled between the first terminal of the first inductive element and the tunable capacitor element;
(c) providing a power amplifier having an input with impedance Z PA , the input being coupled to the first terminal of the second inductive element;
(d) providing a first DC voltage source coupled to the second terminal of the first inductive element;
(e) providing a second DC voltage

Assignees

• Peregrine Semiconductor Corp

Inventors

• Calanca Neil

Classifications

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title

• H03F3/213

  in integrated circuits · CPC title

• H03F1/565 Primary

  using inductive elements · CPC title

• H03F3/195

  in integrated circuits · CPC title

• H03F2200/222

  A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier · CPC title