US3680098A
Expired / Lapsed
US
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Large dynamic range coherent radar processor
Assignee: Syracuse University
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Filing: 1970-11-04
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Granted: 1972-07-25
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Expires: 1990-11-04
Abstract
Abstract A processor for a coherent radar detecting direction of motion can distinguish between targets which oscillate from those having net motion and uses a radar which splits the received signals into two equal parts containing doppler components, shifting one part by 90*. The invention is embodied in the processor whose inputs are these doppler components, usually audio or subaudio frequency signals. The processor shifts the relative phase of the doppler components an additional 90* and combines the shifted components in sum and difference circuits, thus isolating signals due to outgoing target motion in one channel and signals due to incoming target motion in the other channel. The separated signals are then detected, integrated, and combined so as to measure net motion of a moving target. The net motion signal is then applied to a threshold detector whose output indicates an alarm. Unity gain circuitry is used, avoiding automatic gain control whose adaptation time is sometimes prohibitively long.
Inventors
- 👤 Paul E Harris
- 👤 George E Mader
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:51
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/62
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
66 words
Coherent radar signal processing apparatus capable of instantaneous and continuous determination of net approaching or receding target motions over a large range of input signal amplitudes comprising bandpass and phase shift filtering means for collecting and separating approaching and receding target signals into separate channels, then fullwave rectification means in each channel, and then cross connected means in the channels for cross comparison of the channels.
Claim 2
Dependent Claim
66 words
Coherent radar signal processing apparatus capable of instantaneous and continuous determination of net approaching or receding target motions over a large range of input signal amplitudes comprising bandpass and phase shift filtering means for collecting and separating approaching and receding target signals into separate channels, then fullwave rectification means in each channel, and then cross connected means in the channels for cross comparison of the channels.
Claim 3
Dependent Claim
41 words
Apparatus as defined in claim 1 in which the cross connected means comprises attenuator means in each of two channels, the output of each attenuator being fed to a comparator whose other input is the unattenuated value of the other channel.
Claim 4
Dependent Claim
221 words
Coherent radar signal processing apparatus capable of instantaneous and continuous determination of net approaching or receding target motions over a large range of input signal amplitudes comprising bandpass and phase shift filter means in that order in each of two channels where Doppler signals in one channel lead those in the other for approaching targets and lag those in the other for receding targets by a 90* phase difference, cross connected sum and difference means in the two channels following the filter means or separating approaching target signals into one channel and receding target signals into the other channel, means in each channel for full wave rectifying the separated signals and then smoothing the rectified signals to a direct current level, means in the two channels for cross comparing the channels to determine the difference between each channel and an attenuated direct current value of the other channel including a first pair of comparator amplifiers, the comparator outputs being each connected through resistors to one side of a common capacitor and to the inputs of a second pair of comparator amplifiers, the other input of each of the second pair being connected to opposite voltage biases, and indicator means connected to the output of each of the second pair of comparators for reading the voltage of each of the second pair.
Claim 5
Dependent Claim
221 words
Coherent radar signal processing apparatus capable of instantaneous and continuous determination of net approaching or receding target motions over a large range of input signal amplitudes comprising bandpass and phase shift filter means in that order in each of two channels where Doppler signals in one channel lead those in the other for approaching targets and lag those in the other for receding targets by a 90* phase difference, cross connected sum and difference means in the two channels following the filter means or separating approaching target signals into one channel and receding target signals into the other channel, means in each channel for full wave rectifying the separated signals and then smoothing the rectified signals to a direct current level, means in the two channels for cross comparing the channels to determine the difference between each channel and an attenuated direct current value of the other channel including a first pair of comparator amplifiers, the comparator outputs being each connected through resistors to one side of a common capacitor and to the inputs of a second pair of comparator amplifiers, the other input of each of the second pair being connected to opposite voltage biases, and indicator means connected to the output of each of the second pair of comparators for reading the voltage of each of the second pair.
Claim 6
Dependent Claim
208 words
Coherent radar signal processing apparatus having band filter means and phase shift filter means in each of two channels for adding a 90* phase lag between channels, a difference amplifier in each channel, one difference amplifier being preceded by an inverter and each difference amplifier being cross connected from the opposite channel for separating approaching target signals into one channel and receding target signals into the other channel, the filter means and amplifiers each having a unity gain, means in each channel for full wave rectifying the separated signals and then smoothing the rectified signals to a direct current level, means in the two channels for cross comparing the channels to determine the difference between each channel and an attenuated direct current value of the other channel including a first pair of comparator amplifiers having a small voltage bias at one input, the comparator outputs being each connected through a resistor to one side of a common capacitor and to the inputs of a second pair of comparator amplifiers, the other input of each of the second pair being given opposite voltage biases, and indicator means connected to the output of each of the second pair of comparators for reading the voltage of each of the second pair.
Claim 7
Dependent Claim
208 words
Coherent radar signal processing apparatus having band filter means and phase shift filter means in each of two channels for adding a 90* phase lag between channels, a difference amplifier in each channel, one difference amplifier being preceded by an inverter and each difference amplifier being cross connected from the opposite channel for separating approaching target signals into one channel and receding target signals into the other channel, the filter means and amplifiers each having a unity gain, means in each channel for full wave rectifying the separated signals and then smoothing the rectified signals to a direct current level, means in the two channels for cross comparing the channels to determine the difference between each channel and an attenuated direct current value of the other channel including a first pair of comparator amplifiers having a small voltage bias at one input, the comparator outputs being each connected through a resistor to one side of a common capacitor and to the inputs of a second pair of comparator amplifiers, the other input of each of the second pair being given opposite voltage biases, and indicator means connected to the output of each of the second pair of comparators for reading the voltage of each of the second pair.
Claim 8
Dependent Claim
198 words
Coherent radar signal processing apparatus having band filter means and phase shift filter means in each of two channels for adding a 90* phase lag between channels, a difference amplifier in each channel, one difference amplifier being preceded by an inverter and each difference amplifier being cross connected from the opposite channel for separating approaching target signals into one channel and receding target signals into the other channel, the filter means and amplifiers each having a unity gain, a full wave rectifier in each channel connected to the output of a respective difference amplifier, a smoothing filter and buffer connected to each rectifier, cross connected means in the channels for cross comparing the channels including a pair of comparator amplifiers, a polarity inverter connected to the output of one of the pair, a common capacitor connected at one side through two resistors to the output of the last named comparators, inverted in one channel, a second pair of comparators each having one input connected to one side of the capacitor, the second input of the second pair being oppositely voltage biased, and separate indicator means for reading the output voltage of each of the second pair of comparators.
Claim 9
Dependent Claim
198 words
Coherent radar signal processing apparatus having band filter means and phase shift filter means in each of two channels for adding a 90* phase lag between channels, a difference amplifier in each channel, one difference amplifier being preceded by an inverter and each difference amplifier being cross connected from the opposite channel for separating approaching target signals into one channel and receding target signals into the other channel, the filter means and amplifiers each having a unity gain, a full wave rectifier in each channel connected to the output of a respective difference amplifier, a smoothing filter and buffer connected to each rectifier, cross connected means in the channels for cross comparing the channels including a pair of comparator amplifiers, a polarity inverter connected to the output of one of the pair, a common capacitor connected at one side through two resistors to the output of the last named comparators, inverted in one channel, a second pair of comparators each having one input connected to one side of the capacitor, the second input of the second pair being oppositely voltage biased, and separate indicator means for reading the output voltage of each of the second pair of comparators.
References Cited (Backward Citations)
US3046548A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |