Oscillator with variable reactive current frequency control

Claim 2

A controlled oscillator system comprising: oscillator means including a frequency-selective network having at least one reactive circuit element for producing an oscillator output signal at a frequency determined at least in part by said network; current-sampling means coupled in series relation with said reactive element of said oscillator means for providing a current sample having a phase and frequeNcy determined by current in said reactive element; and control means coupled in parallel relationship with said reactive element and to said current-sampling means for varying current flowing in parallel with said reactive element and thereby varying the phase or frequency of oscillation of said controlled oscillator system.

Claim 3

A controlled oscillator system in accordance with claim 1 wherein: said control means comprises voltage-responsive conductive means for varying the amount of current responsive to said current sample which flows in parallel with said reactive element.

Claim 4

A controlled oscillator system comprising: oscillator means including a frequency-selective network having at least one reactive circuit element for producing an oscillator output signal at a frequency determined at least in part by said network; means coupled to said oscillator means for providing a current sample corresponding in phase and frequency to current in said reactive element; and control means comprising a pair of current paths coupled in series with and responsive to said current sample, one of said current paths being coupled in parallel relationship with said reactive element, and voltage-responsive conductive means for controlling the conductivity of said pair of current paths, thereby varying the amount of current which flows in parallel with said reactive element to control the frequency or phase of oscillation of said controlled oscillator system.

Claim 5

A controlled oscillator system comprising: oscillator means including a frequency-selective network having at least one reactive circuit element for producing an oscillator output signal at a frequency determined at least in part by said network; means coupled to said oscillator means for providing a current sample corresponding in phase and frequency to current in said reactive element; and control means comprising a pair of current paths coupled in series with and responsive to said current sample, one of said current paths being coupled in parallel relationship with said reactive element, and voltage-responsive conductive means for controlling the conductivity of said pair of current paths, thereby varying the amount of current which flows in parallel with said reactive element to control the frequency or phase of oscillation of said controlled oscillator system.

Claim 6

A controlled oscillator system comprising: oscillator means including a frequency-selective network having at least one reactive circuit element for producing an oscillator output signal at a frequency determined at least in part by said network; means coupled to said oscillator means for providing a current sample corresponding in phase and frequency to current in said reactive element including a current source; and control means coupled to said current source and responsive to said current sample for completing a current path in parallel relation with said reactive element for varying the phase or frequency of oscillations of said controlled oscillator system.

Claim 7

A controlled oscillator system comprising: oscillator means including a frequency-selective network having at least one reactive circuit element for producing an oscillator output signal at a frequency determined at least in part by said network; means coupled to said oscillator means for providing a current sample corresponding in phase and frequency to current in said reactive element including a current source; and control means coupled to said current source and responsive to said current sample for completing a current path in parallel relation with said reactive element for varying the phase or frequency of oscillations of said controlled oscillator system.

Claim 8

A system as defined in claim 4 and further including: means for controlling current flowing in said current source to synchronize the phase and frequency of said current with current flowing in said reactive element.

Claim 9

A controlled oscillator system in accordance with claim 1 and further comprising: means for coupling a control signal to said control means, said control signal being representative of phase or frequency errors in said oscillator for producing a phase or frequency change in said oscillator output frequency to correct for said phase or frequency error.

Claim 10

Frequency controlling circuit means comprising: a circuit including a reactive circuit element, current-sampling means coupled in series relation with said reactive element for providing a current sample corresponding in phase and frequency to current in said reactive element, a current path of controllable conductivity connected in parallel with said reactive circuit element, current-sampling means coupled in series relation with said reactive circuit element and to said controllable conductivity current path for causing the current in said current path to change in synchronism with changes in phase and frequency of current through said reactive element, and control means coupled to said current path for varying current in said path in response to signals supplied to said control means.

Claim 11

Frequency controlling circuit means comprising: a circuit including a reactive circuit element, current-sampling means coupled in series relation with said reactive element for providing a current sample corresponding in phase and frequency to current in said reactive element, a current path of controllable conductivity connected in parallel with said reactive circuit element, current-sampling means coupled in series relation with said reactive circuit element and to said controllable conductivity current path for causing the current in said current path to change in synchronism with changes in phase and frequency of current through said reactive element, and control means coupled to said current path for varying current in said path in response to signals supplied to said control means.

Claim 12

A controlled oscillator system comprising: an amplifier having a frequency-selective network including at least one reactive circuit element and a regenerative feedback circuit to sustain oscillations; a current source coupled to said frequency-selective network and responsive to current flowing in said reactive element of said frequency-selective network for providing a reactive current, said reactive current Being controlled in phase and frequency by current flowing through said reactive element of said frequency-selective network; means for providing a conduction path for said reactive current in parallel relation to said reactive element of said frequency-selective network; and means coupled to said means for providing a conduction path and responsive to an externally applied control signal to vary the magnitude of current flowing through said conduction path, thereby varying frequency of oscillation of said system.

Claim 13

A controlled oscillator system comprising: an amplifier having a frequency-selective network including at least one reactive circuit element and a regenerative feedback circuit to sustain oscillations; a current source coupled to said frequency-selective network and responsive to current flowing in said reactive element of said frequency-selective network for providing a reactive current, said reactive current Being controlled in phase and frequency by current flowing through said reactive element of said frequency-selective network; means for providing a conduction path for said reactive current in parallel relation to said reactive element of said frequency-selective network; and means coupled to said means for providing a conduction path and responsive to an externally applied control signal to vary the magnitude of current flowing through said conduction path, thereby varying frequency of oscillation of said system.

Claim 14

A controlled oscillator system as defined in claim 8 including current-sampling means coupled in series relation to said reactive circuit element, said current-sampling means further coupled to said current source to control the phase and frequency of current flowing therethrough.

Claim 15

A frequency-controlled oscillator system comprising in combination: an oscillator circuit including a frequency selective network comprising at least one reactive element, means for providing a current sample of current flowing in said reactive element, said means including a current source comprising at least one transistor having base, emitter and collector terminals, and means coupled to said collector terminal of said current source transistor and responsive to external control signals for providing a variable conduction current path in parallel relation with said reactive element.

Claim 16

A frequency-controlled oscillator system comprising in combination: an oscillator circuit including a frequency selective network comprising at least one reactive element, means for providing a current sample of current flowing in said reactive element, said means including a current source comprising at least one transistor having base, emitter and collector terminals, and means coupled to said collector terminal of said current source transistor and responsive to external control signals for providing a variable conduction current path in parallel relation with said reactive element.

Claim 17

A circuit as defined in claim 10 wherein said means for providing a current sample further includes: means for developing a control signal to be applied to said base terminal of said current source transistor, said last-named means coupled to at least said one reactive element of said frequency-selective network to produce a control signal responsive to current flowing in said reactive element to drive said current source in synchronism with said current flowing in said reactive element.

Claim 18

A circuit as defined in claim 11 wherein said means for developing a control signal includes: a variable conduction transistor having a base terminal coupled to said base terminal of said current source transistor, and a collector terminal coupled to said reactive element, and a constant current transistor having base, emitter and collector terminals, said emitter terminal coupled to said collector terminal on said variable conduction transistor, said collector terminal coupled to a power source and said base terminal coupled to a reference potential.

Claim 19

A circuit as defined in claim 10 wherein said means for providing a current path of variable conduction comprises: a first transistor of a pair of differentially coupled transistors, said first transistor having a base terminal coupled to an externally applied control signal, an emitter terminal coupled to said current source, and a collector terminal coupled to a first terminal on said reactive element of said frequency-selective network; and a second transistor of said pair having a base terminal coupled to a direct voltage source, an emitter terminal coupled to said emitter terminal of said first transistor of said pair, and a collector terminal coupled to a second terminal on said reactive element whereby the total current flowing in said current source is divided between said first and second transistor in differing amounts in response to changes in said externally applied control signal thereby varying the frequency of oscillation of said system.

Claim 20

A controlled oscillator system comprising: an amplifier having first and second input terminals, a feedback terminal, and an output terminal; capacitive means coupled from said first input terminal of said amplifier to a reference potential; inductive means having a first and second terminal, said first terminal being coupled to said first input terminal of said amplifier; means for coupling said feedback terminal to said first input terminal of said amplifier, thereby providing regenerative feedback to sustain oScillations in said system; means for coupling said second terminal of said inductive means to said second input terminal of said amplifier; current-sampling means having input and output terminals, said last-named input terminal being coupled to said second terminal of said inductive means, said current-sampling means being responsive to current flowing in said inductive means to produce a current control signal; a reactive current source having output and control terminals, said control terminal being coupled to said output terminal on said current-sampling means, said reactive current source responsive to said current control signal to supply current from said source, whereby said current is in predetermined phase relationship to current flowing in said inductive means; and current-splitting means coupled to said current source for conducting at least a portion of said current flowing in said current source in a parallel path to said inductive means, said current splitting means being responsive to an externally applied control signal to vary the magnitude of current flowing in said parallel path, thereby varying the frequency of oscillation of said system.

Claim 21

A controlled oscillator system comprising: an amplifier having first and second input terminals, a feedback terminal, and an output terminal; capacitive means coupled from said first input terminal of said amplifier to a reference potential; inductive means having a first and second terminal, said first terminal being coupled to said first input terminal of said amplifier; means for coupling said feedback terminal to said first input terminal of said amplifier, thereby providing regenerative feedback to sustain oScillations in said system; means for coupling said second terminal of said inductive means to said second input terminal of said amplifier; current-sampling means having input and output terminals, said last-named input terminal being coupled to said second terminal of said inductive means, said current-sampling means being responsive to current flowing in said inductive means to produce a current control signal; a reactive current source having output and control terminals, said control terminal being coupled to said output terminal on said current-sampling means, said reactive current source responsive to said current control signal to supply current from said source, whereby said current is in predetermined phase relationship to current flowing in said inductive means; and current-splitting means coupled to said current source for conducting at least a portion of said current flowing in said current source in a parallel path to said inductive means, said current splitting means being responsive to an externally applied control signal to vary the magnitude of current flowing in said parallel path, thereby varying the frequency of oscillation of said system.

Claim 22

A controlled oscillator system as defined in claim 14 wherein said current-sampling means includes a variable conduction transistor coupled in series relation with said inductive means to conduct at least a portion of reactive current flowing therethrough.

Claim 23

A controlled oscillator system as defined in claim 14 wherein said reactive current source comprises: a current source transistor having a base terminal coupled to said current-sampling means, and a collector terminal coupled to said current-splitting means to provide in part a current path parallel in relation to said inductive means said current source responsive to signals from said current-sampling means to develop a reactive current sample which is in phase and frequency synchronization with current flowing in said inductive means.

Claim 24

A circuit as defined in claim 16 wherein said current-sampling means comprises a variable conduction transistor coupled in series relation with said inductive means to conduct at least a portion of reactive current flowing therethrough, said current source transistor is constructed in proximity to said variable conduction transistor on a monolithic integrated circuit substrate thereby being thermally coupled thereto, and said current source transistor includes a base-emitter junction area bearing a proportional relationship to the base-emitter area of said variable conduction transistor.

Claim 25

A circuit as defined in claim 14 wherein said current-splitting means comprise: a first transistor having base, collector and emitter terminals wherein said emitter terminal is coupled to said current source, said base terminal is coupled to a source of external control signals, and said collector terminal is coupled to said first terminal of said inductive means and a second transistor having base, collector and emitter terminals wherein said emitter terminal is coupled to said current source, said base terminal is coupled to a direct voltage source and said collector terminal is coupled to a second terminal of said inductive means.

Claim 26

A circuit as defined in claim 18 wherein said first and second transistors share the total current flowing in said current source in a proportion determined by said external control signal applied to said base terminal of said first transistor, and wherein said collector current in said first transistor is in parallel relation with current in said inductive means thereby effecting a change in frequency of operation of said system with changes in said collector current in response to said external control signal.