SSB pulse Doppler sensor and active reflector system
First Claim
1. A microwave Doppler transceiver apparatus comprising:
- a transmit clock signal generator for generating a transmit clock signal;
a pulsed transmit oscillator for producing transmitter RF bursts in response to the transmit clock signal, each burst comprising one or more cycles of a waveform;
an RF quadrature network connected to the transmit oscillator to split the transmitter RF bursts into two phases;
an antenna connected to the RF quadrature network to transmit the transmitter RF bursts, and to receive echoes of the transmitted RF bursts;
quadrature detectors connected to the RF quadrature network to detect in-phase (I) and quadrature (Q) phase components of the RF bursts;
a baseband quadrature network connected to the quadrature detectors to shift the relative phase of the I and Q components by 90 degrees and to provide first and second outputs thereof;
an SSB matrix connected to the first and second outputs of the baseband quadrature network to provide upper and lower sideband outputs.
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Accused Products
Abstract
A dual channel microwave sensor employs single sideband Doppler techniques in innumerable vibration, motion, and displacement applications. When combined with an active reflector, the sensor provides accurate range and material thickness measurements even in cluttered environments. The active reflector can also be used to transmit multi-channel data to the sensor. The sensor is a homodyne pulse Doppler radar with phasing-type Doppler sideband demodulation having a 4-decade baseband frequency range. Ranging is accomplished by comparing the phase of the Doppler sidebands when phase modulated by an active reflector. The active reflector employs a switch or modulator connected to an antenna or other reflector. In one mode, the active reflector is quadrature modulated to provide SSB reflections. Applications for the low-cost system include a mechanical motion/rotation sensor, a robust security alarm, a throat microphone, a stereo guitar pickup, a direction sensitive cardiac monitor, an electronic dipstick, a material thickness/dielectric sensor, a metal smoothness meter, a non-contact electronic readout, an RFID tag, silent “talking” toys, a passive-emitter data link, a beam interrupter, and a gold nugget finder.
195 Citations
72 Claims
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1. A microwave Doppler transceiver apparatus comprising:
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a transmit clock signal generator for generating a transmit clock signal;
a pulsed transmit oscillator for producing transmitter RF bursts in response to the transmit clock signal, each burst comprising one or more cycles of a waveform;
an RF quadrature network connected to the transmit oscillator to split the transmitter RF bursts into two phases;
an antenna connected to the RF quadrature network to transmit the transmitter RF bursts, and to receive echoes of the transmitted RF bursts;
quadrature detectors connected to the RF quadrature network to detect in-phase (I) and quadrature (Q) phase components of the RF bursts;
a baseband quadrature network connected to the quadrature detectors to shift the relative phase of the I and Q components by 90 degrees and to provide first and second outputs thereof;
an SSB matrix connected to the first and second outputs of the baseband quadrature network to provide upper and lower sideband outputs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A short pulse microwave Doppler sensor comprising:
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a pulsed RF oscillator for providing RF bursts;
an antenna for transmitting and receiving RF bursts;
an RF quadrature network having a first port connected to the pulsed RF oscillator, a second port connected to the antenna, a third port connected to an I detector and a fourth port connected to a Q detector;
first and second RF peak detectors which coherently integrate RF pulses from multiple clock repetitions and are respectively connected to the I and Q ports of the RF quadrature network. - View Dependent Claims (15, 16)
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17. A method of sensing short SSB radar pulses, comprising:
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generating RF pulses;
quadrature peak detecting the sum of RF transmitter pulses and reflected transmitter pulses from an object;
integrating two or more RF pulses while quadrature peak detecting the pulses;
SSB demodulating the peak detected signals. - View Dependent Claims (18)
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19. A method of sensing SSB Doppler signals, comprising:
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transmitting RF bursts through an RF quadrature network to an object;
receiving reflected signals from the object at the RF quadrature network;
peak detecting quadrature RF signals from the quadrature network;
phase shifting the detected quadrature RF signals to provide phase shifted I and Q baseband signals;
algebraically summing the phase shifted baseband I and Q signals to form LSB and USB signals. - View Dependent Claims (20)
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21. A method of sensing radar target displacement, comprising:
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rectifying LSB and USB Doppler signals from respective outbound and inbound channels;
integrating the rectified LSB and USB signals;
algebraically summing the integrated LSB and USB signals;
weighting the algebraic sum to reset the outbound channel with a defined signal from the inbound channel and vice-versa;
threshold detecting the weighted sums to provide inbound and outbound detection signals for a defined amount of target movement in a given direction. - View Dependent Claims (22)
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23. A method of sensing radar target vibration, comprising:
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transmitting a pulsed RF burst;
phase shifting the transmitted RF burst and received echo bursts to obtain multiphase RF burst signals;
detecting the multiphase RF burst signals to produce multiphase baseband signals phase shifting the detected baseband signals;
algebraically summing the phase shifted baseband signals to form LSB and USB signals. - View Dependent Claims (24)
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25. A method of sensing bio-mechanical motion, comprising:
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illuminating a moving biological entity or organ with RF energy;
detecting upper Doppler motion sidebands of the RF energy reflecting from or transmitted through the entity or organ in a first channel and lower Doppler motion sidebands in a second channel;
obtaining directional motion information from the detected sidebands. - View Dependent Claims (26, 27, 28, 29, 30)
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31. A method of sensing musical instrument vibrations, comprising:
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illuminating a vibrating component of a musical instrument with RF energy;
detecting upper Doppler motion sidebands of the RF energy reflecting from or transmitted through the vibrating component of the instrument in a first channel and lower Doppler motion sidebands in a second channel;
obtaining vibrational motion information from the detected sidebands. - View Dependent Claims (32, 33, 34, 35)
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36. A method of sensing changes in radar cross-section of a plurality of objects, comprising:
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illuminating at least one object with RF energy;
bringing at least one illuminated object into contact or out of contact with at least another object;
detecting at least one of the upper or lower Doppler sidebands of the RF energy reflecting from or transmitted through at least one illuminated object. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44)
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45. A method of sensing radar range, comprising:
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illuminating a modulated active reflector with RF energy;
detecting upper sideband modulation of reflected energy from the active reflector in a first channel and lower sideband modulation in a second channel;
measuring the phase between the detected upper and lower sideband modulation; and
calculating the range of the active reflector from the measured phase. - View Dependent Claims (46, 47, 48, 49, 50, 51)
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52. A method of sensing a radar beam interruption, comprising:
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illuminating an active reflector with RF energy from a radar;
modulating the active reflector;
detecting a decrease in modulated reflected energy as a result of a blockage of a beam path between the active reflector and the radar. - View Dependent Claims (53, 54)
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55. A method of sensing an RFID tag, comprising:
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illuminating the RFID tag with RF energy from a radar;
modulating an active reflector within the RFID tag to reflect modulated upper and lower sidebands back to the radar;
detecting modulation in at least one of the upper and lower sidebands received by the radar from the RFID tag. - View Dependent Claims (56, 57, 58)
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59. A method of radiolocation, comprising:
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illuminating at least two active reflectors with RF energy from a radar;
modulating the active reflectors to produce upper and lower sidebands;
detecting modulation in at least one of the upper or lower sidebands received by the radar from the active reflectors;
measuring the range to the reflectors by the phase between the detected modulation of the upper and lower sidebands;
calculating the location of at least one of the reflectors or the radar using the measured ranges. - View Dependent Claims (60, 61, 62)
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63. A method of quadrature modulating an active reflector, comprising:
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coupling at least two phase shift networks to the terminals of an active reflector;
switching the phase shift networks across the reflector terminals. - View Dependent Claims (64, 65, 66)
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67. A radar and active reflector system, comprising:
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a radar for transmitting and receiving RF bursts;
a modulated active reflector for reflecting transmitted RF bursts back to the radar;
a detector within the radar for detecting at least one of the USB or LSB reflections from the active reflector. - View Dependent Claims (68, 69)
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70. A rotating object detector, comprising:
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a radar for transmitting RF energy to and receiving reflected energy from the rotating object;
a quadrature detector within the radar for providing I and Q outputs;
a phase comparator to compare the phase of the I and Q outputs to determine the direction of rotation of the object. - View Dependent Claims (71, 72)
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Specification