US3836864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining tacan bearing
Assignee: TDK Micronas GmbH
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Filing: 1973-04-19
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Granted: 1974-09-17
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Expires: 1993-04-19
Abstract
Abstract This invention relates to a method and apparatus for extracting antenna modulation components by phase locking a locally generated sine wave at the desired frequency with the actual antenna modulation. A phase locked oscillator is triggered at predetermined reference points on the received Tacan signal. The output of the oscillator is phase shifted in the direction of coincidence with th received modulation envelope. A comparator compares the phase shifted signal and the envelope of the received signal and generates an error signal if coincidence does not exist. The error signal is fed back and multiplied betwen phase shifted signal; in one case after the phase shifted signal is limited and in another case after the phase shifted signal is further shifted by 90* and limited. In the first case the result of the multiplication is integrated and used to modify the amplitude of the phase shifted signal. In the second case, the result of the multiplication is integrated and controls the amount of the phase shift imparted on the locally generated signal to achieve coincidence.
Inventors
- 👤 M Jezo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:21
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/081; G; G01; G01S; G01S1/00; G01S1/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
159 words
An apparatus for generating a local signal which is coincident in phase and in amplitude with a received signal comprising: a local oscillator for generating said local signal; means coupled to said local oscillator and to said received signal for triggering said local oscillator at a predetermined point on said received signal; means coupled to the output of said local oscillator and to said received signal for comparing said local signal and said received signal and generating an error signal if said local signal and said received signal are not coincident; phase shifting means coupled between said local oscillator and said comparing means; first means responsive to said error signal and coupled between said comparing means and said phase shifting means for altEring the amplitude of said local signal in the direction of coincidence; and second means responsive to said error signal and coupled between said comparing means and said phase shifting means for controlling said phase shifting means.
Claim 2
Independent Claim
159 words
An apparatus for generating a local signal which is coincident in phase and in amplitude with a received signal comprising: a local oscillator for generating said local signal; means coupled to said local oscillator and to said received signal for triggering said local oscillator at a predetermined point on said received signal; means coupled to the output of said local oscillator and to said received signal for comparing said local signal and said received signal and generating an error signal if said local signal and said received signal are not coincident; phase shifting means coupled between said local oscillator and said comparing means; first means responsive to said error signal and coupled between said comparing means and said phase shifting means for altEring the amplitude of said local signal in the direction of coincidence; and second means responsive to said error signal and coupled between said comparing means and said phase shifting means for controlling said phase shifting means.
Claim 3
Dependent Claim
84 words
An apparatus according to claim 1 wherein said first responsive means comprises: first multiplying means for multiplying said error signal with said phase shifted signal to obtain an average amplitude correction signal; and second means coupled between said phase shifting means and said comparing means and having as an input said average amplitude correction signal for multiplying said phase shifted signal by said average amplitude correction signal to alter the amplitude of said local signal in the direction of coincidence with said received signal.
Claim 4
Dependent Claim
75 words
An apparatus according to claim 2 wherein said first multiplying means includes: an amplitude limiter having an input coupled to said phase shifted signal; a first multiplier having a first input coupled to the output of said limiter and a second input coupled to said error signal; and an integrator having an input coupled to the output of said multiplier and having an output which is applied to the input of said second multiplying means.
Claim 5
Dependent Claim
95 words
An apparatus according to claim 1 wherein said second responsive means comprises: a 90* phase shifter having an input coupled to the output of said phase shifter; an amplitude limiter having an input coupled to the output of said 90* phase shifter; a second multiplier having one input coupled to the output of said second limiter and another input coupled to said error signal; and an integrator having an input coupled to the output of said second multiplier and having an output coupled to said phase shifting means for controlling the amount of phase shift.
References Cited (Backward Citations)
US3419814A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |