US3648176A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjacent channel measurement test system
Assignee: Edo Communications and Countermeasures Systems Inc
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Filing: 1970-08-20
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Granted: 1972-03-07
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Expires: 1990-08-20
Abstract
Abstract A system for cancelling or suppressing the amplitude of the carrier and sideband signals of a radio transmitter to facilitate analysis of spurious and noise outputs from the transmitter is disclosed. The system includes means for deriving a carrier cancelling signal from an actual sample of the transmitter output, signal processing circuitry and summing means. Also, an electromechanical signal controller is disclosed capable of continuously correcting the amplitude of the cancellation signal by a selected ratio with respect to the transmitter test signal.
Inventors
- 👤 David R Martin
- 👤 Walter A Sauter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:58
CPC Classifications
H; H04; H04B; H04B17/00; H04B17/10; H04B17/15; H04B17/16
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
191 words
A system for cancelling the carrier frequency output of a radio transmitter to allow the detection and analysis of spurious radiation by the radio transmitter comprising, means for deriving a first continuous sample of the output of a radio transmitter including carrier, modulation, if any, and spurious signals, means for deriving two quadratured component signals from said derived sample of transmitter output, means for deriving a second continuous sample of the output of said same radio transmitter including carrier, modulation, if any, and spurious signals, means for introducing a selected delay into said second sample, individual means for controlling the amplitude of said two quadratured component signals, means for subtractively combining each of said amplitude controlled quadrature component signals with said delayed second sample, means for deriving DC signals proportional to the magnitude of the residual signals output of said subtractive combining means, and means for applying said derived DC signals to said respective amplitude controlling means to adjust said amplitude controlling means to reduce said residual signal to a minimum, an output terminal, and means connected to said subtractive combining means for deriving the radio transmitter residual output of interest.
Claim 2
Independent Claim
191 words
A system for cancelling the carrier frequency output of a radio transmitter to allow the detection and analysis of spurious radiation by the radio transmitter comprising, means for deriving a first continuous sample of the output of a radio transmitter including carrier, modulation, if any, and spurious signals, means for deriving two quadratured component signals from said derived sample of transmitter output, means for deriving a second continuous sample of the output of said same radio transmitter including carrier, modulation, if any, and spurious signals, means for introducing a selected delay into said second sample, individual means for controlling the amplitude of said two quadratured component signals, means for subtractively combining each of said amplitude controlled quadrature component signals with said delayed second sample, means for deriving DC signals proportional to the magnitude of the residual signals output of said subtractive combining means, and means for applying said derived DC signals to said respective amplitude controlling means to adjust said amplitude controlling means to reduce said residual signal to a minimum, an output terminal, and means connected to said subtractive combining means for deriving the radio transmitter residual output of interest.
Claim 3
Dependent Claim
29 words
The combination in accordance with claim 1 wherein said delay introducing means introduces a phase angle offset related to the bandwidth of the carrier and modulation to be cancelled.
Claim 4
Dependent Claim
29 words
The combination in accordance with claim 1 wherein said delay introducing means introduces a phase angle offset related to the bandwidth of the carrier and modulation to be cancelled.
Claim 5
Dependent Claim
43 words
The combination in accordance with claim 1 wherein said delay introducing means is controllable to introduce a delay in said second sample having the following relationship to the radio transmitter channel width: the delay is inversely proportional to the said channel band width.
Claim 6
Dependent Claim
36 words
The combination in accordance with claim 1 wherein said delay means comprises a plurality of lengths of coaxial cable and switch means for selectively connecting said coaxial cable into the path of said second continuous sample.
Claim 7
Dependent Claim
53 words
The combination in accordance with claim 1 wherein said individual amplitude controlling means comprise a pair of continuously variable resistance elements with the signal to be controlled introduced across the resistive element, center taps grounded and wipers movable to derive either a positive or negative polarity reduced amplitude proportion of the signal thereon.
Claim 8
Dependent Claim
27 words
The combination in accordance with claim 5 wherein said individual amplitude controlling means includes motors for driving said wipers, said motors driven by said derived DC signals.
Claim 9
Dependent Claim
36 words
The combination in accordance with claim 5 including means for generating a signal related to velocity and acceleration of said motors, and means for varying the level of said derived DC signals as a function thereof.
Claim 10
Dependent Claim
38 words
The combination in accordance with claim 7 including servoamplifier means for driving said motors wherein said level varying means for said derived DC signals is connected to decrease the gain of said servoamplifiers as a function of velocity.
Claim 11
Independent Claim
154 words
A system for cancelling a selected band of frequencies from a communications channel comprising, first means for continuously sampling the signal content of said communications channel, means for dividing said signal content into two quadrature components, second means for continuously sampling the signal content of said communications channel, means for introducing a predetermined delay into said second sample, means for controlling the amplitude of said quadrature components, means for recombining said amplitude controlled quadrature components, means for combining said recombined amplitude controlled quadrature components with said delayed second sample, means for deriving a control signal related to the level of the output of said last combining means, means for applying sAid control signal to said controlling means to vary the amplitude of said quadrature components to maintain a minimum level at the output of said combining means, and means for passing the residual signal of said communications channel to the output of said system.
Claim 12
Independent Claim
154 words
A system for cancelling a selected band of frequencies from a communications channel comprising, first means for continuously sampling the signal content of said communications channel, means for dividing said signal content into two quadrature components, second means for continuously sampling the signal content of said communications channel, means for introducing a predetermined delay into said second sample, means for controlling the amplitude of said quadrature components, means for recombining said amplitude controlled quadrature components, means for combining said recombined amplitude controlled quadrature components with said delayed second sample, means for deriving a control signal related to the level of the output of said last combining means, means for applying sAid control signal to said controlling means to vary the amplitude of said quadrature components to maintain a minimum level at the output of said combining means, and means for passing the residual signal of said communications channel to the output of said system.
Claim 13
Dependent Claim
41 words
The combination in accordance with claim 9 wherein said amplitude controlling means comprises a pair of variable electromechanical attenuators including a variable resistance element, a wiper, and electrical drive means for adjusting said wiper with respect to said variable resistance element.
Claim 14
Dependent Claim
25 words
The combination in accordance with claim 9 including means responsive to movement of said variable electromechanical attenuator for varying the level of said control signal.
Claim 15
Dependent Claim
38 words
The combination in accordance with claim 11 including servoamplifier means for providing drive current for said variable electromechanical attenuator, said servoamplifier connected to receive input signals from said control signal developing means and from said movement responsive means.
Claim 16
Dependent Claim
40 words
The combination in accordance with claim 12 wherein said servoamplifier means combine said input signals to provide a drive current directly related to the level of said control signal and inversely related to the velocity of said variable electromechanical attenuator.
References Cited (Backward Citations)
US3204047A
Cited
US3544904A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |