TUNABLE MATCHING NETWORK CIRCUIT TOPOLOGY SELECTION

• US 20090267705A1
• Filed: 04/24/2009
• Published: 10/29/2009
• Est. Priority Date: 04/25/2008
• Status: Active Grant

• Current Assignee: WiSpry, Inc (AAC Technologies Holdings Inc.)
• Original Assignee: WiSpry, Inc (AAC Technologies Holdings Inc.)
• Inventors: Morris, Arthur Sherman III
• Granted Patent: US 8,115,572 B2
• Time in Patent Office: Days
• US Class Current: 333/175
• CPC Class Codes: H03H 7/0153 Electrical filters; Controlling thereof
• CPC Class Codes: H03H 7/1708 Comprising bridging elements, i.e. elements in a series path without own reference to ground and spanning branching nodes of another series path H03H7/07 takes precedence
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H03H 7/38 Impedance-matching networks

Abstract

Tunable matching network topologies are disclosed. A network in accordance with the present invention comprises at least one inductor, and at least one tunable capacitor, in parallel with the inductor, wherein the at least one tunable capacitor tunes the at least one inductor self-resonant frequency.

Claims

1. A tunable network, comprising:

at least one inductor; and

at least one tunable capacitor, in parallel with the inductor, wherein the at least one tunable capacitor tunes a self-resonant frequency and a reactive impedance of the at least one inductor.

2. A tunable network comprising the network of claim 1, wherein the tunable matching network is a bypassed-double pi network.

3. The tunable network of claim 2, wherein the bypassed-double pi network has a single variable capacitor in parallel with the at least one inductor.

4. The tunable network of claim 1, wherein a capacitive allocation to the at least one tunable capacitor and the inductor value are selected such that the tunable network has maximized tunability at a lowest frequency of interest and maximized transparency at a highest frequency of interest for respective tuning settings.

5. The tunable network of claim 1, wherein the tunable network is used in a cellular telephone system.

6. A tunable matching network, comprising:

a first inductor coupled to a first port and a first node;

a second inductor, coupled between the first node and a second node;

a first capacitor, coupled between the first node and a ground node;

a second capacitor, coupled between the second node and the ground node;

a third inductor, coupled between the second node and a third node;

a third capacitor, coupled between the third node and the ground node;

a fourth inductor, coupled between the third node and a second port; and

a fourth capacitor, coupled between the first node and the third node, wherein the fourth capacitor is a variable capacitor, wherein the fourth capacitor tunes a self-resonant frequency of the series combination of the first and second inductors.

7. The tunable matching network of claim 6, wherein at least the first inductor is a variable inductor.

8. The tunable matching network of claim 6, wherein the tunable matching network is used in a cellular telephone system.

9. The tunable matching network of claim 8, wherein a capacitive allocation to the at least one tunable capacitor and the inductor value are selected such that the tunable network has maximized tunability at a lowest frequency of interest and maximized transparency at a highest frequency of interest for respective tuning settings.

10. A tunable network, comprising:

a first inductor, a second inductor, and a third inductor, wherein the first inductor, second inductor, and third inductor are connected in series;

a first capacitor, coupled between a series connection of the first inductor and the second inductor and ground;

a second capacitor, coupled between a series connection of the second inductor and the third inductor and ground;

and a third capacitor, in parallel with the second inductor, wherein the third capacitor tunes a self-resonant frequency of the second inductor.

11. The tunable network of claim 10, further comprising a fourth inductor connected in series with the third inductor, a fourth capacitor coupled between a series connection of the third inductor and the fourth inductor and ground, and a fifth capacitor, coupled in parallel with the third capacitor, wherein the fifth capacitor tunes a self-resonant frequency of the third inductor.

12. The tunable network of claim 11, further comprising a sixth capacitor, coupled in parallel with the third capacitor and the fifth capacitor.

13. The tunable network of claim 11, wherein the third capacitor and the fifth capacitor are a single capacitor coupled in parallel with the combination of the second inductor and the third inductor.

14. The tunable network of claim 11, wherein a capacitive allocation to the at least one tunable capacitor and the inductor value are selected such that the tunable network has maximized tunability at a lowest frequency of interest and maximized transparency at a highest frequency of interest for respective tuning settings.