US3631344A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ratio squared predetection combining diversity receiving system
Assignee: TDK Micronas GmbH
•
Filing: 1969-12-12
•
Granted: 1971-12-28
•
Expires: 1989-12-12
Abstract
Abstract A pair of RF diversity signals are heterodyned to two IF signals each having the same center frequency with a given information bandwidth. The two IF signals are routed through separate signal channels. Each channel includes in tandem a first filter having said center frequency and a bandwidth greater than said given bandwidth, a second filter having said center frequency and said given bandwidth, and a continuously variable, voltage controlled attenuator. After said attenuator the IF signals are linearly added to provide a common IF signal for demodulation. The common IF signal is used as a reference signal for a phase comparator in each channel. Each phase comparator compares the phase of its associated IF signal at the output of said second filter to the reference signal and adjusts its associated IF signal for inphase combining thereof. Each channel further includes an out-of-band noise detector coupled to said first filter to produce a control voltage for coupling to the associated one of said attenuators to continuously control the amplitude of the associated one of the IF signals prior to the linear addition thereby achieving the desired ratio squared combining of the IF signals.
Inventors
- 👤 Charles Greenwald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:47
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0837
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
394 words
A diversity receiving system of the ratio squared predetection combining type comprising: a pair of sources of radio frequency signal, the signals of each of said source having a given information bandwidth and random phase relation with respect to each other; first means coupled to said sources to provide first and second intermediate frequency signals each having the same center frequency and a bandwidth greater than said given bandwidth; a first variable attenuation means having a signal input, a signal output and a control terminal; a second variable attenuation means having a signal input, a signal output and a control terminal; second means coupled to the output of said first means to coupled said first intermediate frequency signal having said given bandwidth to said signal input of said first attenuation means; third means coupled to the output of said first means to coupled said second intermediate frequency signal having said given bandwidth to said signal input of said second attenuation means; fourth means coupled to said signal output of each of said first and second attenuation means to combine said first and second intermediate frequency signals having said given bandwidth; fifth means coupled to the output of said second, third and fourth means and said first means to vary the phase relationship of said first and second intermediate frequency signals for inphase combining in said fourth means; sixth means coupled to the output of said first means responsive to the amplitude of the noise of said first intermediate frequency signal outside said given bandwidth to produce a first control signal directly proportional to the amplitude of the noise of said first intermediate frequency signal outside said given bandwidth and to directly couple said first control signal to said control terminal of said first attenuation means to control the amplitude of said first intermediate frequency signal coupled to said fourth means; and seventh means coupled to the output of said first means responsive to the amplitude of the noise of said second intermediate frequency signal outside said given bandwidth to produce a second control signal directly proportional to the amplitude of the noise of said second intermediate frequency signal outside said given bandwidth and to directly couple said second control signal to said control terminal of said second attenuation means to control the amplitude of said second intermediate frequency signal coupled to said fourth means.
Claim 2
Dependent Claim
394 words
A diversity receiving system of the ratio squared predetection combining type comprising: a pair of sources of radio frequency signal, the signals of each of said source having a given information bandwidth and random phase relation with respect to each other; first means coupled to said sources to provide first and second intermediate frequency signals each having the same center frequency and a bandwidth greater than said given bandwidth; a first variable attenuation means having a signal input, a signal output and a control terminal; a second variable attenuation means having a signal input, a signal output and a control terminal; second means coupled to the output of said first means to coupled said first intermediate frequency signal having said given bandwidth to said signal input of said first attenuation means; third means coupled to the output of said first means to coupled said second intermediate frequency signal having said given bandwidth to said signal input of said second attenuation means; fourth means coupled to said signal output of each of said first and second attenuation means to combine said first and second intermediate frequency signals having said given bandwidth; fifth means coupled to the output of said second, third and fourth means and said first means to vary the phase relationship of said first and second intermediate frequency signals for inphase combining in said fourth means; sixth means coupled to the output of said first means responsive to the amplitude of the noise of said first intermediate frequency signal outside said given bandwidth to produce a first control signal directly proportional to the amplitude of the noise of said first intermediate frequency signal outside said given bandwidth and to directly couple said first control signal to said control terminal of said first attenuation means to control the amplitude of said first intermediate frequency signal coupled to said fourth means; and seventh means coupled to the output of said first means responsive to the amplitude of the noise of said second intermediate frequency signal outside said given bandwidth to produce a second control signal directly proportional to the amplitude of the noise of said second intermediate frequency signal outside said given bandwidth and to directly couple said second control signal to said control terminal of said second attenuation means to control the amplitude of said second intermediate frequency signal coupled to said fourth means.
Claim 3
Dependent Claim
135 words
A system according to claim 1, wherein said first means includes a first heterodyne means coupled to one of said sources to produce said first intermediate frequency signal having said given bandwidth, a second heterodyne means coupled to the other of said sources to produce said second intermediate frequency signal having said given bandwidth, first filter means having said center frequency and a bandwidth greater than said given bandwidth coupled to said first heterodyne means to pass said first intermediate frequency signal having said given bandwidth and noise associated therewith outside said given bandwidth, and second filter means having said center frequency and a bandwidth greater than said given bandwidth coupled to said second heterodyne means to pass said second intermediate frequency signal having said given bandwidth and noise associated therewith outside said given bandwidth.
Claim 4
Dependent Claim
19 words
A system according to claim 1, wherein said first and second attenuatIon means each include a voltage controlled attenuator.
Claim 5
Dependent Claim
28 words
A system according to claim 1, wherein said second and third means each include filter means having said center frequency and a bandwidth equal to said given bandwidth.
Claim 6
Dependent Claim
14 words
A system according to claim 1, wherein said fourth means includes a linear adder.
Claim 7
Dependent Claim
57 words
A system according to claim 1, wherein said fifth means includes a first phase comparator means coupled to the output of said second and fourth means, and a second phase comparator means coupled to the output of said third and fourth means, the outputs of said first and second phase comparators being coupled to said first means.
Claim 8
Dependent Claim
86 words
A system according to claim 1, wherein said sixth and seventh means each includes filter means having a center frequency and a bandwidth outside said given bandwidth coupled to said first means to pass out-of-band noise, noise detector means coupled to the output of said filter means, power amplifier means coupled to the output of said detector means and rectifier means coupled to the output of said amplifier means and to the associated one of said first and second attenuation means to control the attenuation thereof.
Claim 9
Dependent Claim
214 words
A system according to claim 1, wherein said first means includes a first heterodyne means coupled to one of said sources to produce said first intermediate frequency signal having said given bandwidth, said first heterodyne means including a first voltage-controlled oscillator, a second heterodyne means coupled to the other of said sources to produce said second intermediate frequency signal having said given bandwidth, said second heterodyne means including a second voltage-controlled oscillator, first filter means having said center frequency and a bandwidth greater than said given bandwidth coupled to said first heterodyne means to pass said first intermediate frequency signal having said given bandwidth and noise associated therewith outside said given bandwidth, and second filter means having said center frequency and a bandwidth greater than said given bandwidth coupled to said second heterodyne means to pass said second intermediate frequency signal having said given bandwidth and noise associated therewith outside said given bandwidth; said second means includes third filter means having said center frequency and a bandwidth equal to said given bandwidth coupled between said first filter means and said first attenuation means; and said third means includes fourth filter means having said center frequency and a bandwidth equal to said given bandwidth coupled between said second filter means and said second attenuation means.
Claim 10
Dependent Claim
73 words
A system according to claim 8, wherein said fifth means includes first phase comparator means coupled to the output of said third filter means and said fourth means, and second phase comparator means coupled to the output of said fourth filter means and said fourth means, the output of said first comparator means being coupled to said first oscillator, and the output of said second comparator means being coupled to said second oscillator.
Claim 11
Dependent Claim
167 words
A system according to claim 9, wherein said sixth means includes fifth filter means having a center frequency and a bandwidth outside said given bandwidth coupled to said first filter means to pass out-of-band noise associated with said first intermediate frequency signal, first noise detector means coupled to the output of said fifth filter means, first power amplifier means coupled to the output of said first detector means, and first rectifier means coupled to the output of said first amplifier means to produce said first control signal; said seventh means includes sixth filter means having a center frequency and a bandwidth outside said given bandwidth coupled to said second filter means to pass out-of-band noise associated with said second intermediate frequenCy signal, second noise detector means coupled to the output of said sixth filter means, second power amplifier means coupled to the output of said second detector means, and second rectifier means coupled to the output of said second amplifier means to produce said second control signal.
References Cited (Backward Citations)
US3048782A
Cited
US3305781A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |