US4267600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modulation monitoring apparatus
Assignee: United States Department of the Navy
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Filing: 1979-12-06
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Granted: 1981-05-12
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Expires: 1999-12-06
Abstract
Abstract An apparatus is described for converting the carrier frequency of a moduld signal sampled from the output of an RF transmitter. The conversion provides a replica of the modulated signal at a predetermined center frequency without regard to the selection of a transmitter channel or to the modulation technique used. The replica is presented to a demodulator which provides an information signal suitable for monitoring the quality of modulation of the transmitted signal.
Inventors
- 👤 Kenneth J. Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:14
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/06; H; H04; H04B; H04B17/00; H04B17/10; H04B17/101; H04B17/104; H04B17/15; H04B17/18; H04B17/30; H04B17/309
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
122 words
Monitoring apparatus for generating an output signal useful for evaluating the modulation quality and adequacy of an RF signal from a transmitter having a plurality of equally spaced channels, without regard to the selection of a channel, comprising: first combining means for combining said RF signal with a first reference signal having a PRF equal to the transmitter channel spacing to produce a first signal of a predetermined frequency, second combining means coupled to said first combining means for combining said first signal with a second reference signal to produce a second signal of a predetermined frequency, and demodulating means coupled to said second combining means to produce said output signal having components proportional to the modulation of the transmitted RF signal.
Claim 2
Dependent Claim
122 words
Monitoring apparatus for generating an output signal useful for evaluating the modulation quality and adequacy of an RF signal from a transmitter having a plurality of equally spaced channels, without regard to the selection of a channel, comprising: first combining means for combining said RF signal with a first reference signal having a PRF equal to the transmitter channel spacing to produce a first signal of a predetermined frequency, second combining means coupled to said first combining means for combining said first signal with a second reference signal to produce a second signal of a predetermined frequency, and demodulating means coupled to said second combining means to produce said output signal having components proportional to the modulation of the transmitted RF signal.
Claim 3
Dependent Claim
27 words
The monitoring apparatus of claim 1 wherein said first reference signal is provided by a pulse generator triggered by an oscillator tuned to the transmitter channel spacing.
Claim 4
Dependent Claim
37 words
The monitoring apparatus of claim 1 wherein said first predetermined frequency signal is obtained by passing the output of said first combining means through a first band-pass filter tuned to pass signals of said first predetermined frequency.
Claim 5
Dependent Claim
34 words
The monitoring apparatus of claim 3 wherein the frequency of said second reference signal is provided by an oscillator tuned to a frequency near the frequency to which said first band-pass filter is tuned.
Claim 6
Dependent Claim
29 words
The monitoring apparatus of claim 4 wherein the output of said second combining means is coupled to a band-pass filter tuned to the predetermined frequency of said second signal.
Claim 7
Dependent Claim
35 words
The monitoring apparatus of claim 5 wherein the value of said first and second references frequencies and the band-passes of said filters are such that the frequency of said second predetermined signal is 10.7 MHz.
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) | 1984-05-11 | 1984-11-10 | 1985-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-11 | 1988-11-10 | 1989-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-11 | 1992-11-10 | 1993-05-12 | $7700.00 | Window Closed / Lapsed |