US3686670A — Receiver for use with a direction finding or rada…

Claim 1

Independent Claim 179 words

A receiver for use with a system having a directional aerial array comprising at least two aerials the receiver having means to accept signals received by the aerial array and to produce an output in response thereto, the output indicating the direction of the source of said signals relative to the aerial array, the receiver comprising processor means to derive from the signals received by each aerial of the array respective trains of pulses, the pulses of each train being in a predetermined phase relationship with the carrier waveform of the respective received signal, means to produce said output as a function of the time difference between the occurrence of pulses in one train and the occurrence of pulses in at least one other said train the output having a maximum amplitude when the time difference tends to zero, and superheterodyne mixer means having a common heterodyne oscillator for mixing the received signals accepted from each aerial, the superheterodyne mixer means substantially reducing the frequency of the carrier waveform of the received signals without changing the phase difference therebetween.

Claim 2

Dependent Claim 179 words

A receiver for use with a system having a directional aerial array comprising at least two aerials the receiver having means to accept signals received by the aerial array and to produce an output in response thereto, the output indicating the direction of the source of said signals relative to the aerial array, the receiver comprising processor means to derive from the signals received by each aerial of the array respective trains of pulses, the pulses of each train being in a predetermined phase relationship with the carrier waveform of the respective received signal, means to produce said output as a function of the time difference between the occurrence of pulses in one train and the occurrence of pulses in at least one other said train the output having a maximum amplitude when the time difference tends to zero, and superheterodyne mixer means having a common heterodyne oscillator for mixing the received signals accepted from each aerial, the superheterodyne mixer means substantially reducing the frequency of the carrier waveform of the received signals without changing the phase difference therebetween.

Claim 3

Dependent Claim 28 words

A receiver as claimed in claim 1 wherein the means to produce said output is adapted to produce said output only when said time difference tends to zero.

Claim 4

Dependent Claim 29 words

A receiver as claimed in claim 1 wherein the processor means comprises means to derive the pulses from alternate nodes of the carrier waveform of the respective received signal.

Claim 5

Dependent Claim 34 words

A receives as claimed in claim 1 wherein the processor means comprises means to shape and to differentiate with respect to time each said received signal waveform to produce said respective trains of pulses.

Claim 6

Dependent Claim 40 words

A receives as claimed in claim 1 wherein the means to produce said output comprises coincidence means to add the amplitudes of respective pulses of each train which respective pulses tend to coincidence as the time difference tends to zero.

Claim 7

Dependent Claim 19 words

A receiver as claimed in claim 1 further including sensing means to sense the amplitude of the received signals.

Claim 8

Dependent Claim 73 words

A receiver as claimed in claim 6 wherein the pulses produced by the processor means do not significantly vary in amplitude with variations in the amplitude of the received signals said sensing means sensing the amplitude of the received signal accepted from at least one of the aerials before the respective train of pulses is derived therefrom, means being provided to modulate the amplitude of said output in response to the sensing means.

Claim 9

Independent Claim 172 words

A system having a directional aerial array comprising at least two aerials, and a receiver to produce an output in response to a signal received by the aerial array, the output indicating the direction of the source of said signals relative to the aerial array, the receiver comprising processor means to derive from the signals received by each aerial of the array respective trains of pulses, the pulses of each train being in a predetermined phase relationship with the carrier waveform of the respective received signal, means to produce an output which is a function of the time difference between the occurrence of pulses in one train and the occurrence of pulses in at least one other said train the output having a maximum amplitude when the time difference tends to zero, and superheterodyne mixer means having a common heterodyne oscillator for mixing the received signals accepted from each aerial, the superheterodyne mixer means significantly reducing the frequency of the carrier waveform of the received signals without changing the phase difference therebetween.

Claim 10

Independent Claim 172 words

A system having a directional aerial array comprising at least two aerials, and a receiver to produce an output in response to a signal received by the aerial array, the output indicating the direction of the source of said signals relative to the aerial array, the receiver comprising processor means to derive from the signals received by each aerial of the array respective trains of pulses, the pulses of each train being in a predetermined phase relationship with the carrier waveform of the respective received signal, means to produce an output which is a function of the time difference between the occurrence of pulses in one train and the occurrence of pulses in at least one other said train the output having a maximum amplitude when the time difference tends to zero, and superheterodyne mixer means having a common heterodyne oscillator for mixing the received signals accepted from each aerial, the superheterodyne mixer means significantly reducing the frequency of the carrier waveform of the received signals without changing the phase difference therebetween.

Claim 11

Dependent Claim 32 words

A system as claimed in claim 8 wherein the aerial array comprises at least three aerials, whereby to indicate the direction of said source relative to the aerial array in two dimensions.

Claim 12

Dependent Claim 34 words

A system as claimed in claim 8 wherein the array has a directional sensitivity whereby the receiver produces an output only when the wavefront of the signal is received by all aerials substantially simultaneously.

Claim 13

Dependent Claim 46 words

A system as claimed in claim 9 wherein the array comprises two aerials of equal size each of which is an array of dipoles, the aerials being arranged side by side with their phase centers disposed a distance apart equal to the width of each aerial.

Claim 14

Dependent Claim 54 words

A system as claimed in claim 8 wherein the array comprises two aerials of equal size each of which is an array of dipoles, the aerials being disposed side by side but overlapped such that the phase centers of the aerials are disposed a distance apart equal to half the width of each aerial.

Claim 15

Dependent Claim 40 words

A receiver as claimed in claim 1 wherein the means to produce said output comprises coincidence means to multiply the amplitudes of respective pulses of each train which respective pulses tend to coincidence as the time difference tends to zero.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1975-08-22	1976-02-21	1976-08-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1979-08-22	1980-02-21	1980-08-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1983-08-22	1984-02-21	1984-08-22	$7700.00	Window Closed / Lapsed

Receiver for use with a direction finding or radar receiving system

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