Patent US3924341A successfully refreshed from Google Patents.
US3924341A
Expired / Lapsed
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Doppler microwave landing system signal simulator
Assignee: TDK Micronas GmbH
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Filing: 1974-06-17
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Granted: 1975-12-09
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Expires: 1994-06-17
Abstract
Abstract A signal simulator for artificially providing the Doppler-type signals as they would be sensed by a receiver at any point within the coverage volume of a Doppler-type air navigation beacon. A plurality of voltage controlled phase shifters providing instantaneous phase shifts precisely controlled by a digital programmer, are employed. The device is capable of simulating the complex Doppler Microwave Landing System transmitted beacon signal at any point within the coverage volume for either the azimuth or elevation coordinate functions, and for this purpose, generates a direct commutated signal, a multipath signal of independently controlled Doppler frequency, and reference signals both direct and reflected. The device is particularly useful for bench testing of the airborne Doppler-type navigation equipment normally used with the ground Doppler Microwave Landing System beacon transmitters.
Inventors
- 👤 Henry Edelsohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:02
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/022; G01S1/028
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
222 words
A device for simulating the signal from a Doppler type, commutated antenna array ground beacon as received at a predetermined remote receiving point, comprising: a signal source operating at a predetermined radio frequency; digital clock means for producing a continuous succession of timing pulses; a first controllable radio frequency phase shifter responsive to said signal source and having a control input; first means including a digital counter and a first D/A converter responsive to said counter, said counter being responsive to said clock means, to generate and apply to said first controllable phase shifter control input, a periodic sawtooth signal, thereby to produce a radio frequency sideband spaced a predetermined amount in frequency from said signal source; second and third controllable radio frequency phase shifters each responsive to said sideband at the output of said first controllable phase shifter, and each having a control input; programmer means for generating and applying to said second and third controllable phase shifter control inputs, signals representative of phase shift programs corresponding to the direct and multipath signal phase variations during commutation of a ground beacon antenna simulated, respectively; and a summer circuit responsive to the outputs of said second and third controlled phase shifters and to said signal source to produce a composite signal including said direct and multipath signals and a reference signal, respectively.
Claim 2
Independent Claim
222 words
A device for simulating the signal from a Doppler type, commutated antenna array ground beacon as received at a predetermined remote receiving point, comprising: a signal source operating at a predetermined radio frequency; digital clock means for producing a continuous succession of timing pulses; a first controllable radio frequency phase shifter responsive to said signal source and having a control input; first means including a digital counter and a first D/A converter responsive to said counter, said counter being responsive to said clock means, to generate and apply to said first controllable phase shifter control input, a periodic sawtooth signal, thereby to produce a radio frequency sideband spaced a predetermined amount in frequency from said signal source; second and third controllable radio frequency phase shifters each responsive to said sideband at the output of said first controllable phase shifter, and each having a control input; programmer means for generating and applying to said second and third controllable phase shifter control inputs, signals representative of phase shift programs corresponding to the direct and multipath signal phase variations during commutation of a ground beacon antenna simulated, respectively; and a summer circuit responsive to the outputs of said second and third controlled phase shifters and to said signal source to produce a composite signal including said direct and multipath signals and a reference signal, respectively.
Claim 3
Dependent Claim
44 words
Apparatus according to claim 1 in which said programming means includes digital circuits for generating separate direct and multipath digital programming signals, said programming signals each comprising a substantially fixed number during the simulated dwell time corresponding to each element of said commutated antenna.
Claim 4
Dependent Claim
39 words
Apparatus according to claim 2 including means associated with said digital circuits for separately controlling the duration of the digital number corresponding to the first element dwell time in each commutation cycle for both said direct and multipath sIgnals.
Claim 5
Dependent Claim
40 words
Apparatus according to claim 3 including first additional means within said digital circuits, responsive to manual predetermination, for selecting the number of said digital numbers, each corresponding to an element dwell time, are included in each of said commutation cycles.
Claim 6
Dependent Claim
52 words
Apparatus according to claim 4 including second additional means within said digital circuits, responsive to manual predetermination, for selecting the simulated directional sense of scan, said means providing increasing digital numbers for successive dwell times for one scan sense and decreasing digital numbers for successive dwell times for the other scan sense.
Claim 7
Dependent Claim
28 words
Apparatus according to claim 5 including third additional means responsive to manual preselection, for causing successive ones of said scan cycles to produce successive scans in alternating senses.
Claim 8
Dependent Claim
38 words
Apparatus according to claim 6 including means responsive to separate manual preselection, for controlling the difference between successive digital programming signals for each of said direct and multipath programming signals, to simulate predetermined direct and multipath angles, respectively.
Claim 9
Dependent Claim
19 words
Apparatus according to claim 1 including a noise source connected to said summer circuit to provide composite signal realism.
Claim 10
Dependent Claim
32 words
Apparatus according to claim 1 in which said signal source to generate said sideband substantially at the frequency of the IF circuits of a receiver to be tested by said simulating device.
Claim 11
Dependent Claim
38 words
Apparatus according to claim 2 including means responsive to separate manual preselection, for controlling the difference between successive digital programming signals for each of said direct and multipath programming signals, to simulate predetermined direct and multipath angles, respectively.
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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |