Variable inductor for LC oscillator

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.