US3603988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse density demodulator
Assignee: Lockheed Martin Corp
•
Filing: 1970-01-06
•
Granted: 1971-09-07
•
Expires: 1990-01-06
Abstract
Abstract Pulse bursts are separated from background pulse trains by first standardizing the heights and widths of all incoming pulses. The standard pulses are passed to an averaging circuit, where the background pulses provide a DC or low frequency component in the output, whereas the arrival of a pulse burst causes a relatively rapid change in the output. These changes are detected from the background by means of a high pass filter.
Inventors
- 👤 George L Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:39
CPC Classifications
H; H03; H03K; H03K9/00; H03K5/00; H03K5/01; H03K5/08; H03K5/082; H04; H04B; H04B1/00; H04B1/06; H04B1/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
65 words
A system for detecting pulse bursts in an incoming train of pulses, said system comprising A. means for counting the pulses received in successive intervals, thereby to provide a repetition rate signal corresponding to the number of pulses received in each of said intervals, and B. means for distinguishing variations in the magnitude of said signal, thereby to distinguish said pulse bursts from background pulses.
Claim 2
Independent Claim
65 words
A system for detecting pulse bursts in an incoming train of pulses, said system comprising A. means for counting the pulses received in successive intervals, thereby to provide a repetition rate signal corresponding to the number of pulses received in each of said intervals, and B. means for distinguishing variations in the magnitude of said signal, thereby to distinguish said pulse bursts from background pulses.
Claim 3
Dependent Claim
43 words
The system defined in claim 1 A. including a pulse standardizer connected to standardize the incoming pulses, and B. in which said counting means is an averaging circuit connected to receive said standardized pulses and provide said repetition rate signal in response thereto.
Claim 4
Dependent Claim
25 words
The system defined in claim 2 in which said averaging circuit has a time constant that is less than the duration of a pulse burst.
Claim 5
Dependent Claim
16 words
The system defined in claim 2 in which said distinguishing means is a high pass filter.
Claim 6
Dependent Claim
84 words
The system defined in claim 4 in which said high pass filter comprises A. a differential amplifier having a pair of input terminals and providing an output corresponding to the difference between the voltages applied to said input terminals, B. means connecting one of said input terminals to receive the output of said averaging circuit C. a low-pass filter connected to filter the output of said averaging circuit and apply the low-frequency components resulting therefrom to the other of said differential amplifier input terminals.
Claim 7
Dependent Claim
78 words
A receiver for the detection of pulse bursts of radio frequency energy, said receiver comprising A. a demodulator connected to demodulate the incoming radio frequency signals, B. means for counting the pulses from the demodulator over successive intervals, thereby to provide a repetition rate signal corresponding to the number of pulses received in each of said intervals, and C. means for distinguishing variations in the magnitude of said signal, thereby to distinguish said pulse bursts from background pulses.
Claim 8
Dependent Claim
78 words
A receiver for the detection of pulse bursts of radio frequency energy, said receiver comprising A. a demodulator connected to demodulate the incoming radio frequency signals, B. means for counting the pulses from the demodulator over successive intervals, thereby to provide a repetition rate signal corresponding to the number of pulses received in each of said intervals, and C. means for distinguishing variations in the magnitude of said signal, thereby to distinguish said pulse bursts from background pulses.
Claim 9
Dependent Claim
43 words
The system defined in claim 6 A. including a pulse standardizer connected to standardize the incoming pulses, and B. in which said counting means is an averaging circuit connected to receive said standardized pulses and provide said repetition rate signal in response thereto.
Claim 10
Dependent Claim
25 words
The system defined in claim 7 in which said averaging circuit has a time constant that is less than the duration of a pulse burst.
Claim 11
Dependent Claim
16 words
The system defined in claim 7 in which said distinguishing means is a high pass filter.
Claim 12
Dependent Claim
84 words
The system defined in claim 9 in which said high pass filter comprises A. a differential amplifier having a pair of input terminals and providing an output corresponding to the differeNce between the voltages applied to said input terminals, B. means connecting one of said input terminals to receive the output of said averaging circuit, C. a low-pass filter connected to filter the output of said averaging circuit and apply the low-frequency components resulting therefrom to the other of said differential amplifier input terminals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |