Dynamic digital time interval discriminator and method
AssigneeMotorola, Inc.
InventorJuris Stauers
Life of this patent
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Abstract
Circuitry for indicating the occurrence of a predetermined separation time between adjacent pairs of pulses in a sequence of pulses including a first counter having a first relatively high frequency clock signal applied thereto and the sequence of pulses applied to reset the counter for each pulse, a second counter having a relatively low frequency clock signal applied thereto with the second counter counting the total number of cycles from an initial or starting time, and comparators for comparing the number of cycles in the first counter to the number of cycles in the second counter and providing output signals when the comparison indicates that the separation time between adjacent pairs of pulses is within a predetermined range.
Claims12
A dynamic digital time interval discriminator for indicating the occurrence of a predetermined separation time between pairs of pulses in a sequence of pulses, which sequence is changing in repetition rate, the discriminator comprising:
- (a) first counting means having a clock input terminal adapted to receive a first clock signal at a first predetermined frequency, said first counting means having a reset input terminal adapted to receive the sequence of pulses thereon and a plurality of output terminals;
- (b) second counting means having a clock input terminal adapted to receive a second clock signal at a second predetermined frequency substantially different than said first predetermined frequency, said second counting means having an enable input terminal adapted to receive an enable signal thereon and a plurality of output terminals;
- (c) comparator means having a first plurality of input terminals coupled to the output terminals of said first counting means, a second plurality of input terminals coupled to the output terminals of said second counting means, and an output terminal for comparing signals at the outputs of said first and second counting means and providing an output signal when the signals compare;
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- (d) output means having an input terminal coupled to the output terminal of said comparator means, a reset terminal coupled to the reset terminal of said first counting means, and an output for providing a signal indicative of the occurrence of the predetermined time.
A dynamic digital time interval discriminator for indicating the occurrence of a predetermined separation time between pairs of pulses in a sequence of pulses, which sequence is decreasing in repetition rate, the discriminator comprising:
- (a) first counting means having a clock input terminal, a reset input terminal and a plurality of output terminals;
- (b) second counting means having a clock input terminal, an enable signal input terminal and a plurality of output terminals;
- (c) Doppler radar means having an output connected to the reset input of said first counting means for providing a sequence of Doppler pulses thereon;
- (d) first signal generating means connected to the clock input terminal of said first counting means for providing a first clock signal at a first predetermined frequency relatively high compared to the sequence of Doppler pulses;
- (e) second signal generating means connected to the clock input terminal of said second counting means for providing a second clock signal at a second predetermined frequency substantially lower than said first predetermined frequency;
- (f) enable signal generating means connected to the enable signal input terminal of said second counting means for supplying an enable signal thereto;
- (g) comparator means having a first plurality of input terminals connected to the output terminals of said first counting means, a second plurality of input terminals connected to the output terminals of said second counting means, and an output terminal for comparing signals at the outputs of said first and second counting means and providing an output signal when the signals compare;
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- (h) output means having an input terminal connected to the output terminal of said comparator means, a reset terminal coupled to the reset terminal of said first counting means, and an output for providing a signal indicative of the occurrence of the predetermined time.
In a sequence of pulses, which sequence is decreasing in repetition rate, a method of indicating when the separation between adjacent pulses reaches a predetermined time period, said method comprising the steps of:
- (a) providing a first signal at a frequency much higher than the repetition rate of the sequence of pulses;
- (b) providing a second signal at a frequency much lower than the frequency of the first signal;
- (c) counting the number of cycles in the first signal between each adjacent pair of pulses in the sequence;
- (d) counting the total number of cycles in the second signal from an initial time;
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- (e) comparing the counts to each other, each pulse of the sequence, and providing an output signal when the counts are substantially equal.
Dependencies are inferred from the claim text.