Patent US4249257A successfully refreshed from Google Patents.
US4249257A
Expired / Lapsed
US
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Radio frequency signals analyzer
Assignee: United States Department of the Navy
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Filing: 1977-09-01
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Granted: 1981-02-03
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Expires: 1997-09-01
Abstract
Abstract An analyzer for analyzing radio frequency signals from an FM/PM transmitterithout prior knowledge of the transmitting frequency. The RF signal is sampled and fed to a mixer where it is mixed with the output from a comb generator having a PRF equal to the transmitter channel spacing. The signal out of the mixer is filtered to remove all but the desired frequency components. The filtered signal is fed to a frequency discriminator which provides a demodulated form of the transmitted RF signal and is fed to various parameter indicators.
Inventors
- 👤 Kenneth J. Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:23
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; G; G01; G01R; G01R23/00; G01R23/16; G01R23/165; H04B17/00; H04B17/10; H04B17/15; H04B17/16
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
110 words
Apparatus for analysis of FM and PM radio frequency signals transmitted by a multi-channel radio frequency transmitter having a plurality of equally spaced channels without regard to the selection of a channel, comprising: (a) means for sampling said transmitted radio frequency signals; (b) means for generating a first signal having a frequency spectrum wherein each frequency is separated from an adjacent frequency by a distance equal to the channel spacing of said transmitter; (c) means coupled to said sampling means and to said generating means for mixing said first signal and said sampled signal thereby to produce an output including a replica of said transmitted signal at a predetermined frequency.
Claim 2
Dependent Claim
110 words
Apparatus for analysis of FM and PM radio frequency signals transmitted by a multi-channel radio frequency transmitter having a plurality of equally spaced channels without regard to the selection of a channel, comprising: (a) means for sampling said transmitted radio frequency signals; (b) means for generating a first signal having a frequency spectrum wherein each frequency is separated from an adjacent frequency by a distance equal to the channel spacing of said transmitter; (c) means coupled to said sampling means and to said generating means for mixing said first signal and said sampled signal thereby to produce an output including a replica of said transmitted signal at a predetermined frequency.
Claim 3
Dependent Claim
21 words
The apparatus of claim 1 further comprising a bandpass filter coupled to said mixer means for passing only said replica signal.
Claim 4
Dependent Claim
27 words
The apparatus of claim 1 further comprising means coupled to said mixer means for processing said replica signal to determine the operating characteristics of said transmitted signal.
Claim 5
Dependent Claim
13 words
The apparatus of claim 1 wherein said generating means is a comb generator.
Claim 6
Dependent Claim
16 words
The apparatus of claim 4 wherein said comb generator is of the step recovery diode type.
Claim 7
Dependent Claim
22 words
The apparatus of claim 5 wherein said comb generator has a pulse repetition frequency equal to the channel spacing of said transmitter.
Claim 8
Dependent Claim
19 words
The apparatus of claim 2 wherein said bandpass filter is tuned to the predetermined frequency of the replica signal.
Claim 9
Dependent Claim
13 words
The apparatus of claim 2 wherein said generating means is a comb generator.
Claim 10
Dependent Claim
16 words
The apparatus of claim 8 wherein said comb generator is of the step recovery diode type.
Claim 11
Dependent Claim
22 words
The apparatus of claim 9 wherein said comb generator has a pulse repetition frequency equal to the channel spacing of said transmitter.
Claim 12
Dependent Claim
12 words
The apparatus of claim 1 wherein said predetermined frequency is 200 kHz.
Claim 13
Dependent Claim
18 words
The apparatus of claim 2 wherein the bandpass of said bandpass filter is 150 kHz to 250 kHz.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |