Injection tuned resonant circuits

A tunable oscillator, comprising:

• an LC tank circuit comprising an inductor and a capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• and
• an inductive element coupled with said inductor adapted and arranged to inject said AC signal from said inductive element into said inductor;
• wherein said impedance is formed by an insulating material.

A tunable oscillator, comprising:

• an LC tank circuit comprising an inductor and a capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• and
• a band pass filter to isolate a tuning frequency for injection into said inductor and said capacitor.

A tunable oscillator, comprising:

• an LC tank circuit comprising an inductor, a capacitor, and a negative resistance in parallel with at least one of said inductor and said capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• and
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal;
• wherein
• said LC tank circuit is not within a loop of said phase locked loop.

A tunable oscillator, comprising:

• an LC tank circuit comprising an inductor, a capacitor, and a negative resistance in parallel with at least one of said inductor and said capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• and
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal;
• wherein
• said phase locked loop comprises a second LC tank circuit.

A tunable oscillator, comprising:

• an LC tank circuit comprising an inductor, a capacitor, and a negative resistance in parallel with at least one of said inductor and said capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• and
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal;
• wherein
• a directional coupler between said AC signal and said LC tank circuit to limit a signal flow back from said LC tank circuit.

A method of tuning an oscillator, comprising:

• injecting an AC signal corresponding to a desired oscillation frequency into an oscillator circuit;
• injecting a phase-shifted representation of said AC signal into said oscillator circuit, wherein said phase-shifted representation of said AC signal is shifted 90° with respect to said AC signal, and said AC signal, and said phase-shifted representation of said AC signal are each presented to a common node of said oscillator circuit;
• and
• whereby said oscillator circuit is tuned to said desired oscillation frequency.

Apparatus for tuning an oscillator, comprising:

• means for injecting an AC signal corresponding to a desired oscillation frequency into an oscillator circuit, wherein said oscillator circuit is an LC tank circuit oscillator;
• whereby said oscillator circuit is tuned to said desired oscillation frequency;
• and
• a first flip/flop clocked by a frequency signal output from said LC tank circuit.

A data communication device, comprising:

• a data receiver;
• and
• a tuned oscillator, said tuned oscillator comprising:
• an LC tank circuit comprising an inductor, a capacitor, a negative resistance in parallel with at least one of said inductor and said capacitor, and a first flip/flop clocked by a frequency signal output from said LC tank circuit, and
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit.

A tunable oscillator comprising:

• an LC tank circuit comprising an inductor and a capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• and
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal, wherein said LC tank circuit is not within a loop of said phase locked loop.

A tunable oscillator comprising:

• an LC tank circuit comprising an inductor and a capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• and
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal, wherein said phase locked loop comprises a second LC tank circuit.

A tunable oscillator comprising:

• an LC tank circuit comprising an inductor and a capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal;
• and
• a directional coupler between said AC signal and said LC tank circuit to limit a signal flow back from said LC tank circuit.

A data communication device, comprising:

• a data receiver;
• and
• a tuned oscillator, said tuned oscillator comprising:
• an LC tank circuit comprising an inductor, and a capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• and
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal, wherein said LC tank circuit is not within a loop of said phase locked loop.

A data communication device, comprising:

• a data receiver;
• and
• a tuned oscillator, said tuned oscillator comprising:
• an LC tank circuit comprising an inductor, and a capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• and
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal, wherein said phase locked loop comprises a second LC tank circuit.

A data communication device, comprising:

• a data receiver;
• and
• a tuned oscillator, said tuned oscillator comprising:
• an LC tank circuit comprising an inductor, and a capacitor;
• an impedance in communication with said LC tank circuit, said impedance being adapted and arranged to allow injection of an AC signal corresponding to a desired oscillation frequency of said LC tank circuit;
• a phase locked loop adapted to provide a frequency control signal;
• at least one component in said LC tank circuit being adjustable under the control of said frequency control signal;
• and
• a directional coupler between said AC signal and said LC tank circuit to limit a signal flow back from said LC tank circuit.