US3916406A — Jamming cancellation device

Claim 1

Independent Claim 142 words

In a system for decreasing the effect of interference signals on radar operation, the combination comprising; interference signal detection means having a long response time to incoming signals, transmitter-receiver frequency slew means, trigger means electrically connected to the output of said interference signal detection means and adapted to actuate said frequency slew means upon receipt of a predetermined level of output from said detection means, timing means electrically connected to be actuated by said trigger means for controlling the time of operation of said frequency slew means, and free-running multi-vibrator means electrically connected to and adapted to cooperate with said timing means to control the operation of said frequency slew means, whereby said automatic frequency slew means is actuated upon receipt of an effective interference signal, and operates to change the frequency of said transmitter-receiver to eliminate the effect of interference signals.

Claim 2

Dependent Claim 142 words

In a system for decreasing the effect of interference signals on radar operation, the combination comprising; interference signal detection means having a long response time to incoming signals, transmitter-receiver frequency slew means, trigger means electrically connected to the output of said interference signal detection means and adapted to actuate said frequency slew means upon receipt of a predetermined level of output from said detection means, timing means electrically connected to be actuated by said trigger means for controlling the time of operation of said frequency slew means, and free-running multi-vibrator means electrically connected to and adapted to cooperate with said timing means to control the operation of said frequency slew means, whereby said automatic frequency slew means is actuated upon receipt of an effective interference signal, and operates to change the frequency of said transmitter-receiver to eliminate the effect of interference signals.

Claim 3

Dependent Claim 76 words

The combination such as that defined in claim 1 wherein said interference signal detection means includes; integrator means having a long time constant, said integrator means being electrically connected to the input of the system, and adapted to provide an output signal representative of the interference signal average power level, and actuation means responsive to the output of said integrator means to actuate said frequency slew means in response to the interference signal average power level.

Claim 4

Dependent Claim 54 words

The combination such as that defined in claim 2 wherein; said trigger means includes multi-vibrator means electrically connected to the output of said second integrator means and adapted to be controlled thereby, and first relay means electrically connected to the output of said multi-vibrator means for controlling the excitation of said frequency slew means.

Claim 5

Dependent Claim 137 words

The system such as that defined in claim 3 wherein said timing means includes; a minimum time multi-vibrator, a maximum time multi-vibrator, and a coincidence circuit, said minimum time multi-vibrator being electrically connected to the output of said trigger means whereby it is actuated when the interference input signal actuates said trigger means, said maximum time multi-vibrator being electrically connected to the output of said minimum time multi-vibrator and adapted to be actuated thereby, said coincidence circuit being electrically connected to said maximum time multi-vibrator to provide a control valve for passage of signals from said free-running multi-vibrator, whereby said minimum time multi-vibrator and said maximum time multi-vibrator provide a time interval for operation of said frequency slew means, and said coincidence circuit is enabled for the period of operation of said mInimum and maximum time multi-vibrators.

Claim 6

Dependent Claim 59 words

A system such as that defined in claim 4 including; an ''''or'''' circuit connected to the output of said free-running multi-vibrator means to provide a path for the output of said free-running multi-vibrator means to said coincidence circuit, whereby a signal is provided at the output of said coincidence circuit to control the operation of said frequency slew means.

Claim 7

Dependent Claim 80 words

A system such as that defined in claim 5 wherein said frequency slew means comprises; a transmitter-receiver magnetron tuning device for varying the frequency of the radar transmitter-receiver, a slew motor operably connected to said magnetron tuning drive to actuate said tuning drive, said first relay being operable to connect said slew motor to a source of alternating current when said relay is actuated whereby said slew motor is actuated upon receipt of interference at the input of said system.

Claim 8

Dependent Claim 45 words

A system such as that defined in claim 6 including; polarity selector means electrically connected to the output of said free-running multi-vibrator means and to said slew motor for controlling the direction of rotation of said slew motor when said frequency slew system is actuated.

Claim 9

Dependent Claim 138 words

A system such as that defined in claim 7 wherein; said polarity reversal means includes, a vacuum tube having its control grid electrically connected to the output of said free-running multi-vibrator means whereby the conduction of said vacuum is controlled by said free-running multi-vibrator means, a second relay connected to the plate circuit of said vacuum tube, said second relay having a plurality of contacts part of which are connected to a contact of the first relay whereby upon actuation of said first relay, the contacts of said second relay are maintained in a fixed position, and connecting means electrically connecting the cathode of said vacuum tube to a contact of said first relay whereby upon actuation of said first relay said cathode is open-circuited so that said vacuum tube thereafter has no control over said second relay.

Claim 10

Dependent Claim 22 words

A system such as that defined in claim 7 including; reversing means for reversing the direction of rotation of said slew motor.

Claim 11

Dependent Claim 56 words

The combination as defined in claim 9 wherein; said reversing means includes, actuating means controlled by said magnetron tuning drive and said coincidence means whereby said slew motor is reversed when the frequency limit of the magnetron is reversed, and said slew motor''s rotation is braked when a terminating signal is emitted from said coincidence means.

Claim 12

Dependent Claim 119 words

The combination as defined in claim 10 wherein; said reversing means includes, a thyratron, a third relay and a microswitch, said thyratron having a control grid electrically connected to the output of said coincidence means and to said microswitch, said microswitch being operably connected to said magnetron tuning drive, whereby said thyratron is adapted to be ionized by a terminating signal from said coincidence means and by operation of said microswitch due to the rotation of said magnetron tuning drive, said third relay being operably connected to said thyratron, and to a source of direct current through said first and second relays so that upon ionization of said thyratron, the direction of rotation of said slew motor is reversed.

Claim 13

Dependent Claim 169 words

In a system for decreasing the effect of interference signals on radar operation, the combination comprising; first interference detection means for measuring the average power level of incoming interference signals, second interference detection means connected to the input of said system for measuring the average power level of incoming interference signals, said first interference detection means having a short response time to incoming signals, and said second interference detection means having a slow response time to incoming signals, coast means and automatic track indicator means electrIcally connected to and adapted to be actuated by said first interference signal detection means whereby the radar is rendered insensitive to interference signals when the average power level of the interference signals reaches a predetermined power level and the target positional information is preserved while the coast means is in operation, frequency slew means operably connected to said second interference signal detection means for changing the frequency of operation of the radar upon detection of effective interference signals by said second interference detector.

Claim 14

Dependent Claim 169 words

In a system for decreasing the effect of interference signals on radar operation, the combination comprising; first interference detection means for measuring the average power level of incoming interference signals, second interference detection means connected to the input of said system for measuring the average power level of incoming interference signals, said first interference detection means having a short response time to incoming signals, and said second interference detection means having a slow response time to incoming signals, coast means and automatic track indicator means electrIcally connected to and adapted to be actuated by said first interference signal detection means whereby the radar is rendered insensitive to interference signals when the average power level of the interference signals reaches a predetermined power level and the target positional information is preserved while the coast means is in operation, frequency slew means operably connected to said second interference signal detection means for changing the frequency of operation of the radar upon detection of effective interference signals by said second interference detector.

Claim 15

Dependent Claim 102 words

The combination as defined in claim 12 wherein said first interference detection means comprises; integrator means for receiving the interference signals from the radar system, and for averaging the power level of the signals, electronic valve means connected to the output of said integrator means and adapted to be controlled thereby, whereby said electronic valve means becomes non-conducting when the average power level of the interference signals reaches a predetermined magnitude, and actuation means connected to the output of said electronic valve means and actuating said coast and said automatic track indicator means in response to the output of said integrator means.

Claim 16

Dependent Claim 100 words

The combination as defined in claim 12 wherein said automatic frequency slew means comprises; trigger means electrically connected to the output of said second interference detection means for initiating a frequency slew operation when the incoming interference reaches a predetermined level, timing means connected in series with the output of said trigger means and adapted to be actuated thereby for determining the maximum and minimum time of operation of frequency slew means, and frequency slew direction control means connected to said timing means and said trigger means for controlling the direction and rate of slew of said frequency slew means.

Claim 17

Dependent Claim 134 words

The combination as defined in claim 14 wherein said timing means comprises; a minimum time multi-vibrator connected in series with said trigger means for establishing the minimum time of operation of said frequency slew means, maximum time multi-vibrator means electrically connected to the output of said minimum time multi-vibrator means and adapted to be actuated thereby for establishing the maximum time of operation of said frequency slew means, coincidence means having a control means electrically connected to the output of said maximum time multi-vibrator means for providing a path for a terminating pulse to terminate said frequency slew operation, and random time free-running multi-vibrator means having its output coupled to said coincidence means for providing a random pulse to said coincidence means when it is rendering conductive to thereby terminate the frequency slew operation.

Claim 18

Dependent Claim 95 words

The combination as defined in claim 15 wherein said frequency slew direction control means comprises; polarity selector means connected to the output of said free-running multi-vibrator means and controlled thereby for controlling the direction of frequency slew upon actuation of frequency slew means, and reversing means connected to the output of said coincidence means and to a frequency slew motor whereby the direction of rotation of a frequency slew motor is reversed when a terminating pulse issues from said coincidence means, and when the frequency limit of the radar is approached during the slewing operation.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-10-27	1979-04-28	1979-10-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-10-27	1983-04-28	1983-10-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-10-27	1987-04-28	1987-10-28	$7700.00	Window Closed / Lapsed

Jamming cancellation device

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