摘要:
A radar sensor is described that includes a radar transmitter, a radar receiver configured to receive reflected returns of signals output by the radar transmitter, and a signal processing unit configured to process signals received by the radar receiver. The signal processing unit includes a comparator, a first filter comprising an output coupled to a reference input of the comparator, and a second filter comprising an output coupled to a signal input of the comparator. The first and second filters are configured to receive a common input related to the reflected returns. The first filter is configured to have a time constant such that a rise time of the first filter output is faster than a rise time of the second filter output.
摘要:
A radar sensor is described that includes a radar transmitter, a radar receiver configured to receive reflected returns of signals output by the radar transmitter, and a signal processing unit configured to process signals received by the radar receiver. The signal processing unit includes a comparator, a first filter comprising an output coupled to a reference input of the comparator, and a second filter comprising an output coupled to a signal input of the comparator. The first and second filters are configured to receive a common input related to the reflected returns. The first filter is configured to have a time constant such that a rise time of the first filter output is faster than a rise time of the second filter output.
摘要:
In one aspect, a method of radar altimeter operation including a time dependent gain control is described. The method comprises triggering a Sensitivity Time Control (STC) gain control signal at a pulse repetition frequency (PRF) of a transmit pulse to attenuate interference from at least one of an antenna leakage signal and a signal reflected from equipment. The method also includes shaping the STC gain control signal from no attenuation at a first time, before a transmitter sends the transmit pulse, to a stable maximum attenuation at the time the transmitter sends the transmit pulse, to no attenuation at a second time, after the transmitter sends the transmit pulse. The method also includes matching a bandwidth of an intermediate frequency (IF) amplifier to the pulse width of a transmitted pulse.
摘要:
In one aspect, a method of radar altimeter operation, the altimeter including a high frequency counter coupled to a processor is described. The method comprises providing a continuous wave to the high frequency counter upon receipt of a transmit pulse, counting the cycles of the continuous wave, discontinuing counting of the continuous wave cycles upon receipt of a return pulse, outputting a count from the high frequency counter to the processor, and operating the processor to convert the count to an altitude.
摘要:
A radar processor for controlling detonation of a munition and operable to receive a detonation altitude from an external source is provided. The radar processor is configured to set a first range gate and a reference range gate based on the received detonation altitude, and cause a radar transmitter to operate in a continuous wave mode, for a predetermined period, upon receipt of radar return signals through the first range gate. The radar processor calculates a velocity of the munition from continuous wave return signals, and calculates a time delay for outputting a detonation signal based on the received detonation altitude, the calculated velocity, and a reference altitude of the munition, the altitude of the munition calculated based upon receipt of radar return signals through the reference range gate. The radar transmitter operates in a pulse mode while the munition is outside the reference range gate.
摘要:
A method of delaying propagation of a radio frequency (RF) signal through a circuit is described. The method comprises receiving data that represents a delay time interval, providing an RF signal when a start pulse triggers a memory device, initiating a count through the delay time interval based on receipt of a start pulse, and outputting the RF signal after the delay time interval has expired.
摘要:
A method for controlling a detonation altitude of a radar equipped munition is described. The method includes calculating a velocity of the munition while the munition is at an altitude greater than the desired detonation altitude, determining when the munition is at a reference altitude, and calculating a time representing when the vehicle will reach the desired detonation altitude based on the calculated velocity and determined reference altitude. The method also includes generating a fusing signal to detonate the munition after the calculated time has passed.
摘要:
In one aspect, a method of radar altimeter operation including a time dependent gain control is described. The method comprises triggering a Sensitivity Time Control (STC) gain control signal at a pulse repetition frequency (PRF) of a transmit pulse to attenuate interference from at least one of an antenna leakage signal and a signal reflected from equipment. The method also includes shaping the STC gain control signal from no attenuation at a first time, before a transmitter sends the transmit pulse, to a stable maximum attenuation at the time the transmitter sends the transmit pulse, to no attenuation at a second time, after the transmitter sends the transmit pulse. The method also includes matching a bandwidth of an intermediate frequency (IF) amplifier to the pulse width of a transmitted pulse.
摘要:
A method of compensating for component errors within a radar altimeter is described. The method includes periodically switching transmit pulses from a transmit antenna to a programmable delay device, calculating an altitude based on a transmit pulse received from the programmable delay device, comparing the calculated altitude to an expected altitude, the expected altitude based on a pre-set delay through the programmable delay device, and compensating an altitude measured by the radar altimeter, based on transmit pulses output through the transmit antenna, by an error correction amount based on a difference between the calculated altitude and expected altitudes.
摘要:
A method of compensating for component errors within a radar altimeter is described. The method includes periodically switching transmit pulses from a transmit antenna to a programmable delay device, calculating an altitude based on a transmit pulse received from the programmable delay device, comparing the calculated altitude to an expected altitude, the expected altitude based on a pre-set delay through the programmable delay device, and compensating an altitude measured by the radar altimeter, based on transmit pulses output through the transmit antenna, by an error correction amount based on a difference between the calculated altitude and expected altitudes.