Variable inductor for LC oscillator

• US 8,860,521 B2
• Filed: 12/19/2012
• Issued: 10/14/2014
• Est. Priority Date: 12/19/2012
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel IP Corporation (Intel Corporation)
• Inventors: Ahmed, Rizwan, Roberts, Curtiss, Tsai, Chi Taou
• Primary Examiner(s): Gannon, Levi
• Application Number:
  US13/720,705
• Publication Number:
  US 20140167867A1
• Time in Patent Office: 664 Days
• Field of Search: 331/36.C, 331/36.L, 331/117.FE, 331/117.R, 331/167, 331/181, 336/220, 336/223, 336/225, 336/226, 336/232, 333/137, 333/220, 333/223, 333/225, 333/226, 333/232
• US Class Current: 331/181
• CPC Class Codes: H01F 2021/125 Printed variable inductor with taps, e.g. for VCO
• CPC Class Codes: H01F 21/12 discontinuously variable, e.g. tapped
• CPC Class Codes: H01F 29/00 Variable transformers or inductances not covered by group H01F21/00 tap change devices H01H9/0005
• CPC Class Codes: H03B 5/124 the means comprising a voltage dependent capacitance
• CPC Class Codes: H03B 5/1256 the means comprising a variable inductance

Abstract

A variable inductor is disclosed. In accordance with some embodiments of the present disclosure, a variable inductor may comprise a single-turn conductor comprising a first inductor terminal, a second inductor terminal, a first base portion extending from the first inductor terminal to a first intersection location, a second base portion extending from the second inductor terminal to a second intersection location, and a switched portion extending from the first intersection location to the second intersection location, and a switch comprising a first conductive terminal coupled to the first intersection location and a second conductive terminal coupled to the second intersection location.

Claims

1. A variable inductor, comprising:

a magnetically isolated single-turn conductor, comprising;

a first inductor terminal;

a second inductor terminal;

a first base portion extending from the first inductor terminal to a first intersection location;

a second base portion extending from the second inductor terminal to a second intersection location; and

a switched portion extending from the first intersection location to the second intersection location; and

a switch comprising a first conductive terminal coupled to the first intersection location and a second conductive terminal coupled to the second intersection location.

2. The variable inductor of claim 1, wherein the single-turn conductor is formed on a single layer of conductive material.

3. The variable inductor of claim 2, wherein no portion of the single-turn conductor formed on the single layer of conductive material overlaps a route formed on a second layer of conductive material.

4. The variable inductor of claim 1, wherein the switch comprises a transistor.

5. The variable inductor of claim 1, wherein the length of the switched portion is greater than the combined length of the first base portion and the second base portion.

6. The variable inductor of claim 1, wherein the length of the switched portion is less than the combined length of the first base portion and the second base portion.

7. The variable inductor of claim 1, wherein the single-turn conductor is indented proximate to the switch.

8. A voltage-controlled oscillator, comprising:

an LC resonator comprising a variable capacitor and a variable inductor, the variable inductor comprising;

a magnetically isolated single-turn conductor comprising;

a first inductor terminal coupled to a first capacitor terminal of the variable capacitor;

a second inductor terminal coupled to a second capacitor terminal of the variable capacitor;

a first base portion extending from the first inductor terminal to a first intersection location;

a second base portion extending from the second inductor terminal to a second intersection location; and

a switched portion extending from the first intersection location to the second intersection location; and

a switch comprising a first conductive terminal coupled to the first intersection location and a second conductive terminal coupled to the second intersection location;

wherein the inductor is configured to have a first inductance value if the switch is on and a second inductance value if the switch is off; and

wherein the voltage-controlled oscillator is configured to oscillate at one or more frequencies within a first range of frequencies if the switch is in a first state and at one or more frequencies within a second range of frequencies if the switch is in a second state.

9. The voltage-controlled oscillator of claim 8, wherein the single-turn conductor is formed on a single layer of conductive material.

10. The voltage-controlled oscillator of claim 9, wherein no portion of the single-turn conductor formed on the single layer of conductive material overlaps a route formed on a second layer of conductive material.

11. The voltage-controlled oscillator of claim 8, wherein the switch comprises an transistor.

12. The voltage-controlled oscillator of claim 8, wherein the length of the switched portion is greater than the combined length of the first base portion and the second base portion.

13. The voltage-controlled oscillator of claim 8, wherein the length of the switched portion is less than the combined length of the first base portion and the second base portion.

14. The voltage-controlled oscillator of claim 8, wherein the single-turn conductor is indented proximate to the switch.

15. The voltage-controlled oscillator of claim 8, wherein the first range of frequencies does not overlap with the second range of frequencies.

16. The voltage-controlled oscillator of claim 15, wherein:

the voltage-controlled oscillator is configured to oscillate at a first frequency within the first range of frequencies if the variable capacitor has a first capacitance value and the switch is in the first state;

the voltage-controlled oscillator is configured to oscillate at a second frequency within the first range of frequencies if the variable capacitor has a second capacitance value and the switch is in the first state;

the voltage-controlled oscillator is configured to oscillate at a third frequency within the second range of frequencies if the variable capacitor has a first capacitance value and the switch is in the second state; and

the voltage-controlled oscillator is configured to oscillate at a fourth frequency within the second range of frequencies if the variable capacitor has a second capacitance value and the switch is in the second state.

17. A method, comprising:

operating a voltage-controlled oscillator at a first frequency, the voltage-controlled oscillator comprising an LC-resonator with a variable inductor including a magnetically isolated single-turn conductor;

receiving a first signal instructing the voltage-controlled oscillator to operate at a second frequency;

switching the variable inductor from a first inductance value to a second inductance value; and

operating the voltage controlled oscillator at a second frequency.

18. The method of claim 17, comprising:

receiving a second signal instructing the voltage-controlled oscillator to operate at the first frequency; and

switching the variable inductor from the second inductance value to the first inductance value.