US3704423A — Adf with remote digital tuning

Claim 1

Independent Claim 303 words

A remotely controlled digitally tuned superheterodyne receiver capable of covering a wide frequency range comprising; a manual switch settable to the decimal indication of a selected frequency and providing a digitally coded output signal equivalent to the decimal setting thereof; a plurality of electrically reactive elements having parameters variable by means of a control voltage applied thereto; a plurality of electrically reactive elements having fixed parameters; diode band switching means for combining, in accordance with a first bias voltage applied to said diode means, said fixed parameter elements with said variable parameter elements to provide a plurality of resonant circuits each which may be tuned through a particular band of frequencies within the frequency range of the receiver by variation of the control of said variable parameter elements; first logic means for recognizing an output signal of said manual switch as corresponding to a frequency within a particular band and providing a bias voltage for said diode means to cause said diode means to combine resonant circuits tunable within said particular band; a local oscillator having a variable frequency output; a standard oscillator having a fixed frequency output; second logic means responsive to the output signal of said manual switch for dividing the frequency of the output of said local oscillator by a number having a constant relationship to the selected frequency of said switch; means for comparing the frequency of the output of said local oscillator with that of said standard oscillator to develop a feedback voltage for controlling the frequency of said local oscillator so that the divided value thereof equals the frequency of said standard oscillator; and means applying said feedback voltage as the control voltage for said variable parameter elements for tuning said resonant circuits, one of which constitutes the means determining the frequency of said local oscillator output.

Claim 2

Dependent Claim 303 words

A remotely controlled digitally tuned superheterodyne receiver capable of covering a wide frequency range comprising; a manual switch settable to the decimal indication of a selected frequency and providing a digitally coded output signal equivalent to the decimal setting thereof; a plurality of electrically reactive elements having parameters variable by means of a control voltage applied thereto; a plurality of electrically reactive elements having fixed parameters; diode band switching means for combining, in accordance with a first bias voltage applied to said diode means, said fixed parameter elements with said variable parameter elements to provide a plurality of resonant circuits each which may be tuned through a particular band of frequencies within the frequency range of the receiver by variation of the control of said variable parameter elements; first logic means for recognizing an output signal of said manual switch as corresponding to a frequency within a particular band and providing a bias voltage for said diode means to cause said diode means to combine resonant circuits tunable within said particular band; a local oscillator having a variable frequency output; a standard oscillator having a fixed frequency output; second logic means responsive to the output signal of said manual switch for dividing the frequency of the output of said local oscillator by a number having a constant relationship to the selected frequency of said switch; means for comparing the frequency of the output of said local oscillator with that of said standard oscillator to develop a feedback voltage for controlling the frequency of said local oscillator so that the divided value thereof equals the frequency of said standard oscillator; and means applying said feedback voltage as the control voltage for said variable parameter elements for tuning said resonant circuits, one of which constitutes the means determining the frequency of said local oscillator output.

Claim 3

Dependent Claim 105 words

A receiver as claimed in claim 1 with additionally a second plurality of fixed parameter reactive elements; second diode switch means for connecting, in accordance a second bias voltage applied thereto, at least one each of said second fixed reactive elements to resonate with and partially determine the frequency of the circuits connected by said diode band switching means and third logic means controlling said second switching means for recognizing a segment of frequencies within each band of frequencies and for providing said second bias voltage whereby said second elements are connected in circuit for tuning a segment of frequencies in each band of frequencies.

Claim 4

Dependent Claim 120 words

A receiver as claimed in claim 1 wherein said first logic means are connected to solve logic equations defining a logically true condition for a first range of digitally coded output signals from said manual switch and thereby control said band switching means so that said fixed parameter elements are connected in resonant circuits tunable through frequencies corresponding to said first range of digitally coded output signals and wherein said first logic means solve different logic equations defining a logically true condition for another range of digitally coded output signals thereby controlling said band switching means so that said fixed parameter elements are connected in resonant circuits tunable through frequencies corresponding to said other range of digitally coded output signals.

Claim 5

Dependent Claim 73 words

A receiver as claimed in claim 1 wherein said second logic means includes a digital counter presettable to said number having a constant relationship to said selected frequency, said counter receiving said local oscillator output and generating an output pUlse upon counting a sum of signal cycles of said local oscillator equal to said number, said counter output pulse being compared with the output of said standard oscillator to develop said feedback voltage.

Claim 6

Dependent Claim 21 words

A receiver as claimed in claim 4 wherein said counter output pulse is connected to reset said counter to said number.

Claim 7

Dependent Claim 42 words

A receiver as claimed in claim 4 wherein said counter responds to one phase of output from said local oscillator and with additionally means interposed between said local oscillator and said counter for selectively inverting the phase of said local oscillator output.

Claim 8

Dependent Claim 44 words

A receiver as claimed in claim 6 wherein said means for selectively inverting phase includes means responsive to said counter output pulse whereby said phase inverter means inverts the phase of said local oscillator output during alternate periods of output pulses from said counter.

Claim 9

Dependent Claim 254 words

A remotely controlled digitally tuned superheterodyne receiver said receiver being at one location and including there a mixer and a local oscillator for converting the frequency of received signals to a constant intermediate frequency, comprising: a manual selector switch located remotely from said receiver, said switch being settable to a decimal number indicating the frequency to be tuned by said receiver and providing an electrical digitally coded output signal equivalent to said number; electrical conductors for transmitting said digitally coded output signal from said switch to said receiver; a plurality of resonant circuits in said receiver each of which includes an element having a reactance variable by means of an applied control voltage for tuning through a particular band of frequencies within the tuning rang e of said receiver; diode band switching means in said receiver for connecting in operation particular ones of said resonant circuits in accordance with a bias voltage applied thereto; logic means in said receiver responsive to the coded output of said manual switch to provide bias voltage for said diode band switching means; and a frequency synthesizer serving as the local oscillator for said receiver, said synthesizer including logic means responsive to the coded output of said manual switch for controlling the frequency of the output of said synthesizer at a value offset from the frequency set on said manual switch by an amount equal to the intermediate frequency of the receiver, said synthesizer also providing a voltage output for controlling said variable reactance elements of said resonant circuits.

Claim 10

Dependent Claim 254 words

A remotely controlled digitally tuned superheterodyne receiver said receiver being at one location and including there a mixer and a local oscillator for converting the frequency of received signals to a constant intermediate frequency, comprising: a manual selector switch located remotely from said receiver, said switch being settable to a decimal number indicating the frequency to be tuned by said receiver and providing an electrical digitally coded output signal equivalent to said number; electrical conductors for transmitting said digitally coded output signal from said switch to said receiver; a plurality of resonant circuits in said receiver each of which includes an element having a reactance variable by means of an applied control voltage for tuning through a particular band of frequencies within the tuning rang e of said receiver; diode band switching means in said receiver for connecting in operation particular ones of said resonant circuits in accordance with a bias voltage applied thereto; logic means in said receiver responsive to the coded output of said manual switch to provide bias voltage for said diode band switching means; and a frequency synthesizer serving as the local oscillator for said receiver, said synthesizer including logic means responsive to the coded output of said manual switch for controlling the frequency of the output of said synthesizer at a value offset from the frequency set on said manual switch by an amount equal to the intermediate frequency of the receiver, said synthesizer also providing a voltage output for controlling said variable reactance elements of said resonant circuits.

Claim 11

Dependent Claim 134 words

A receiver as claimed in claim 8 wherein said synthesizer includes a constant frequency oscillator; a voltage controlled variable frequency oscillator; a counter for counting output cycles of said variable frequency oscillator, said counter being preset by said synthesizer logic means to a number equalling the desired synthesizer output frequency divided by the frequency of said constant frequency oscillator and providing an output signal upon the accumulation of a sum of said variable frequency oscillator cycles equal to said preset number; and means for controlling the frequency of said variable frequency oscillator, said frequency control means including means for comparing the phase of output from said constant frequency oscillator with the phase of output from said counter to develop an oscillator control voltage, said oscillator control voltage also serving to tune said resonant circuits.

Claim 12

Dependent Claim 46 words

A receiver as claimed in claim 9 wherein said variable frequency oscillator produces a bipolar output signal, said counter responding to a particular polarity of said variable frequency oscillator output, and with additionally: means for selectively reversing the phase of the output of said variable oscillator.

Claim 13

Dependent Claim 29 words

A receiver as claimed in claim 10 wherein said phase reversing means includes means controlled by said coded output from said manual switch for enabling said phase reversing means.

Claim 14

Dependent Claim 39 words

A receiver as Claimed in claim 11, with additionally: means responsive to said counter output for causing said phase reversing means to reverse the phase of said variable frequency oscillator output during alternate periods of output from said counter.

Claim 15

Dependent Claim 99 words

A receiver as claimed in claim 12 wherein said phase reversing means and said enabling means comprises: an inverter providing an output opposite in phase to the output of said variable frequency oscillator; gate means controlling the conduction of output from said inverter to said counter or output from said variable frequency oscillator to said counter; and a flip-flop operated by output from said counter for enabling said gating means so that direct phase output and opposite phase output from said variable frequency oscillator is applied in alternation to said counter according to the output state of said flip-flop.

Claim 16

Dependent Claim 261 words

A digitally tuned superheterodyne receiver including a mixer and a local oscillator for converting the frequency of received signals to a constant intermediate frequency, comprising: a frequency selector upon which the decimal representation of the frequency of the signal to be received may be set and providing a digitally coded output signal equivalent to the decimal setting thereof; logic means for converting said digitally coded signal into band selection signals; an element having an electrically variable reactance; a plurality of elements having fixed reactances; band selection means controlled by said band selection signals for connecting particular ones of said fixed reactance elements to said variable reactance element to provide resonant circuits tunable within a particular band of frequencies of the total tuning range of the receiver; a second plurality of elements having fixed reactances; means for selectively connecting at least one each of said second plurality elements to each of said resonant circuits so that variation of said variable reactance element from maximum to minimum reactance with none of said second plurality of elements connected tunes one of said resonant circuits through a segment of frequencies within a particular band and a similar variation of reactance with at least one of said second plurality of elements connected to one of said resonant circuits tunes said resonant circuit through a segment of frequencies contiguous to the first mentioned segment of frequencies; and second logic means responsive to said digitally coded output signal and to said band selection signals for controlling the connection of said second plurality of elements to said resonant circuits.

Claim 17

Dependent Claim 261 words

A digitally tuned superheterodyne receiver including a mixer and a local oscillator for converting the frequency of received signals to a constant intermediate frequency, comprising: a frequency selector upon which the decimal representation of the frequency of the signal to be received may be set and providing a digitally coded output signal equivalent to the decimal setting thereof; logic means for converting said digitally coded signal into band selection signals; an element having an electrically variable reactance; a plurality of elements having fixed reactances; band selection means controlled by said band selection signals for connecting particular ones of said fixed reactance elements to said variable reactance element to provide resonant circuits tunable within a particular band of frequencies of the total tuning range of the receiver; a second plurality of elements having fixed reactances; means for selectively connecting at least one each of said second plurality elements to each of said resonant circuits so that variation of said variable reactance element from maximum to minimum reactance with none of said second plurality of elements connected tunes one of said resonant circuits through a segment of frequencies within a particular band and a similar variation of reactance with at least one of said second plurality of elements connected to one of said resonant circuits tunes said resonant circuit through a segment of frequencies contiguous to the first mentioned segment of frequencies; and second logic means responsive to said digitally coded output signal and to said band selection signals for controlling the connection of said second plurality of elements to said resonant circuits.

Claim 18

Dependent Claim 50 words

A receiver as claimed in claim 14 with additionally: a frequency synthesizer serving as the local oscillator of said receiver, said synthesizer developing a voltage for controlling its own frequency; and means applying said synthesizer control voltage to said variable reactance elements to control the tuning of said resonant circuits.

Claim 19

Dependent Claim 115 words

A receiver as claimed in claim 15 wherein said frequency synthesizer comprises: a standard oscillator; a voltage controlled variable frequency oscillator; a counter for counting output cycles of said variable frequency oscillator; logic means responsive to said digitally coded signal for presetting said counter so that said counter will generate an output signal upon counting a number of cycles from said variable frequency oscillator equal to the frequency to be received offset by the intermediate frequency of the receiver and divided by the frequency of said standard oscillator; and means for comparing the phase of signals from said standard oscillator with output signals from said counter to provide control voltage for said variable frequency oscillator.

Claim 20

Dependent Claim 73 words

A receiver as claimed in claim 15 wherein said variable frequency oscillator signal is bipolar and said counter responds only to one polarity of said variable frequency oscillator signal, and with additionally; means for selecTively inverting the polarity of said variable frequency oscillator signal prior to application to said counter whereby the effective sum accumulated by said counter is increased by a fractional part of a cycle of said variable frequency oscillator signal.

Claim 21

Dependent Claim 120 words

A receiver as claimed in claim 17 wherein said means for selectively inverting polarity includes: a flip-flop to which the output of said counter is applied; means responsive to said digitally coded signal for enabling said flip-flop so that the output state of said flip-flop changes with each consecutive output signal from said counter; an inverter to which output from said variable frequency oscillator is applied and which provides an output similar to said variable frequency oscillator output but of opposite polarity; and gate means responsive to the output state of said flip-flop for applying the output of said variable frequency counter to said counter without polarity inversion or with polarity inversion according to the output state of said flip-flop.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1975-11-28	1976-05-29	1976-11-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1979-11-28	1980-05-29	1980-11-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1983-11-28	1984-05-29	1984-11-28	$7700.00	Window Closed / Lapsed

Adf with remote digital tuning

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag