Patent US3766481A successfully refreshed from Google Patents.
US3766481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiant energy receiver
Assignee: TDK Micronas GmbH
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Filing: 1970-04-20
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Granted: 1973-10-16
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Expires: 1990-04-20
Abstract
Abstract A satellite navigation system including a single-channel receiver for producing output signals from which the geographical position of a ship may be calculated. The receiver utilizes a first intermediate frequency (IF) which is approximately equal to the mean difference of the frequencies of two incoming carriers. This makes it possible to use a single channel because the first IF of one carrier is almost exactly the same as that of the other. A filter may then be used for any further signal separation. Doppler and refraction frequencies may also be easily extracted.
Inventors
- 👤 P Rodgers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:50
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/01; G; G01; G01S; G01S11/00; G01S11/02; G01S11/10
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
183 words
A receiving system comprising: an antenna having a bandwidth capable of receiving first and second signals of different frequencies, fm1 + fa1 and fm2 + fa2, respectively, where fm1 and fm2 are both substantially larger than both fa1 and fa2; first means for producing a first auxiliary signal of a frequency equal to (fm1 + fm2)/2 + fa3; a first mixer for mixing said received signals with said first auxiliary signal to provide one first output signal of a frequency (fm1 - fm2)/2 + fa1 - fa3 and another first output signal of a frequency (fm1 - fm2)/2 - fa2 + fa3; second means for producing a second auxiliary signal of a frequency fa4 - fa5 where fa4 >> fa5 and fa4 (fm1 - fm2)/2 fa6 where fa6 << (fm1 - fm2)/2; and a second mixer for mixing said second auxiliary signal with said first output signals to provide one second output signal with a frequency of fa6 + fa1 fa3 + fa5 and another second output signal of fa6 -fa2+fa3+fa5, to provide IF signals to be processed within a common IF channel.
Claim 2
Dependent Claim
183 words
A receiving system comprising: an antenna having a bandwidth capable of receiving first and second signals of different frequencies, fm1 + fa1 and fm2 + fa2, respectively, where fm1 and fm2 are both substantially larger than both fa1 and fa2; first means for producing a first auxiliary signal of a frequency equal to (fm1 + fm2)/2 + fa3; a first mixer for mixing said received signals with said first auxiliary signal to provide one first output signal of a frequency (fm1 - fm2)/2 + fa1 - fa3 and another first output signal of a frequency (fm1 - fm2)/2 - fa2 + fa3; second means for producing a second auxiliary signal of a frequency fa4 - fa5 where fa4 >> fa5 and fa4 (fm1 - fm2)/2 fa6 where fa6 << (fm1 - fm2)/2; and a second mixer for mixing said second auxiliary signal with said first output signals to provide one second output signal with a frequency of fa6 + fa1 fa3 + fa5 and another second output signal of fa6 -fa2+fa3+fa5, to provide IF signals to be processed within a common IF channel.
Claim 3
Dependent Claim
152 words
The invention as defined in claim 1, including a filter connected from said second mixer to pass said one second output signal and to reject the other, a phase detector connected from said flter, a loop filter connected from said phase detector, a voltage-controlled oscillator connected from said loop filter, said first means including a frequency multiplier connected from the output of said voltage controlled oscillator, a local oscillator, means responsive to the outputs of both of said oscillators for producing a Doppler output signal having a frequency fa7 + E (fd + fr) where fa7 is an intermediate frequency, K is a constant, fd is the Doppler frequency, and fr is the refraction frequency, a thrid mixer responsive to said Doppler signal and said other second signal for producing a refraction signal, a phase detector connected from said third mixer, said local oscillator being connected to both of said phase detectors.
Claim 4
Dependent Claim
73 words
The invention as defined in claim 1, including a first phase-locked loop connected from said first mixer to said first means, and first loop including a voltage controlled oscillator, third means responsive to the output of said oscillator and the output of said first mixer for producing an output signal of a frequency f1 + Dfd , where f1 is substantially constant, D is a constant, and fd is a variable Doppler frequency.
Claim 5
Dependent Claim
16 words
The invention as defined in claim 3, including a phase-locked loop connected from said third means.
Claim 6
Dependent Claim
84 words
The invention as defined in claim 1, including a phase-locked loop having a voltage-controlled oscillator, said first means being responsive to the output of said oscillator for maintaining the phase of said one of said output signal constant, fa1 being defined as fa1 -fb + fd + fr, fa2 being defined as fa2 -Kfb + Kfd + (1/K)fr, K being defined as K fm2/fm1, fa3 being defined as fa3 -fb + fd + fr + fi, fm1, fm2, fb, and fi being constant frequencies.
Claim 7
Dependent Claim
150 words
The invention as defined in claim 5, wherein separation means responsive to said other output signal and to the output of said oscillator are provided for producing an output signal proporational to fr, said separation means including second means responsive to said output signals for producing a signal of a frequency fc defined by fc fd - fe + C(1-K) (fd - (1/K)fr) + ff where fc, fe, C, and ff are constant, third means responsive to the output of said voltage-controlled oscillator for producing a signal of a frequency, fg, defined by fg fh - C (1 -K) (fd + fr) - fj where fh and fj are constant, and a mixer to mix said signals of frequencies fc and fg to produce an output signal of a frequency, fk, defined by fk fm - (C (1 - K) (1+ K)/K)fr - fn where fm and fn are constants.
Claim 8
Dependent Claim
144 words
The invention as defined in claim 5, wherein separation means responsive to said other output signal and to the output of said oscillator are provided for producing an output signal proportional to fr, said separation means including second means responsive to said output signals for producing a signal of a frequeNcy, fc, defined by fc fw - fe + C(1 - K) (fd - (1/K)fr), where fd, fe, C, and ff are constant, third means responsive to the output of said voltage-controlled oscillator for producing a signal of a frequency, fp, defined by fp fq - fs + ( C (1 -K)/K) (fd + fr), where fq and fs are constants, and a mixer to mix said signals of frequencies fc and fp to produce an output signal of a frequency ft, defined by ft -fv + ( C(1 -K) (1 + K)/k) fd.
Claim 9
Dependent Claim
165 words
In a system for separating two frequency shifts of first and second carrier signals hving first and second frequencies fm1-fb + fd + fr and fm2 - Kfb + Kfd + (1/K) fr, respectively, fm1, fm2, and K being constant, fd and fr being variable, the combination comprising: means responsive to said first carrier signal for producing an output signal proportional to fd + fr; means responsive to said second carrier signal for producing an output signal proportional to Afd + Bfr, where A and B are constants, one of said constants A and B being larger than the other, one of said constants A and B being unity; and means including at least one down-converter and filter means operating from said output signals for discriminating between fd and fr after said down-conversion, for producing utilization signals of sum and difference frequencies of said output signals such that one of the frequencies fd and fr is absent in one of said sum and difference frequencies.
Claim 10
Dependent Claim
165 words
In a system for separating two frequency shifts of first and second carrier signals hving first and second frequencies fm1-fb + fd + fr and fm2 - Kfb + Kfd + (1/K) fr, respectively, fm1, fm2, and K being constant, fd and fr being variable, the combination comprising: means responsive to said first carrier signal for producing an output signal proportional to fd + fr; means responsive to said second carrier signal for producing an output signal proportional to Afd + Bfr, where A and B are constants, one of said constants A and B being larger than the other, one of said constants A and B being unity; and means including at least one down-converter and filter means operating from said output signals for discriminating between fd and fr after said down-conversion, for producing utilization signals of sum and difference frequencies of said output signals such that one of the frequencies fd and fr is absent in one of said sum and difference frequencies.
Claim 11
Independent Claim
332 words
A system for receiving, in a single receiver channel, first and second phase coherent radio frequency carriers separated in frequency, said carriers being modulated for transmission of data from a satellite and exhibiting Doppler frequency shift due to satellite motion and a refraction frequency component, comprising: first conversion means including a first mixer and means connected thereto for generating a local oscillator signal at a controllable frequency, said oscillator signal being generated substantially at a frequency spaced from the midpoint between said first and second carrier frequencies by a predetermined separation frequency to produce first and second IF signals corresponsing to said first and second carriers; antenna means of sufficiently broad-band characteristic to receive both said first and second carriers and supply them to said first conversion means; a first IF channel responsive to the output of said first conversion means, said channel having a pass band including said first and second IF signals; second conversion means responsive to said first IF channel and for down-converting the output of said first IF channel to provide second IF signals from a second IF channel; a stable oscillator providing a first output at a frequency lower than said first IF channel pass band and at least second and third synchronous signals having frequencies at predetermined multiplies of said first output; first phase detector means responsive to said second IF signals and said stable oscillator first output to decode said data modulation; a phase lock loop for frequency tracking said first carrier, said loop including said controlled frequency oscillator associated with said first conversion means and also said first and second IF channels and said first phase detector means; Doppler signal detecting means responsive to said second and third stable oscillator signals and the ouTput of said controlled frequency oscillator for extracting said Doppler and refraction frequencies; and refraction signal detecting means responsive to said second IF channel output and said Doppler signal detecting means output for producing an output signal containing said refraction signal.
Claim 12
Independent Claim
332 words
A system for receiving, in a single receiver channel, first and second phase coherent radio frequency carriers separated in frequency, said carriers being modulated for transmission of data from a satellite and exhibiting Doppler frequency shift due to satellite motion and a refraction frequency component, comprising: first conversion means including a first mixer and means connected thereto for generating a local oscillator signal at a controllable frequency, said oscillator signal being generated substantially at a frequency spaced from the midpoint between said first and second carrier frequencies by a predetermined separation frequency to produce first and second IF signals corresponsing to said first and second carriers; antenna means of sufficiently broad-band characteristic to receive both said first and second carriers and supply them to said first conversion means; a first IF channel responsive to the output of said first conversion means, said channel having a pass band including said first and second IF signals; second conversion means responsive to said first IF channel and for down-converting the output of said first IF channel to provide second IF signals from a second IF channel; a stable oscillator providing a first output at a frequency lower than said first IF channel pass band and at least second and third synchronous signals having frequencies at predetermined multiplies of said first output; first phase detector means responsive to said second IF signals and said stable oscillator first output to decode said data modulation; a phase lock loop for frequency tracking said first carrier, said loop including said controlled frequency oscillator associated with said first conversion means and also said first and second IF channels and said first phase detector means; Doppler signal detecting means responsive to said second and third stable oscillator signals and the ouTput of said controlled frequency oscillator for extracting said Doppler and refraction frequencies; and refraction signal detecting means responsive to said second IF channel output and said Doppler signal detecting means output for producing an output signal containing said refraction signal.
Claim 13
Dependent Claim
80 words
Apparatus according to claim 9 in which said second conversion means is defined as producing a pair of frequency spaced signals at said second IF frequency, corresponding discretely to said first and second carriers in down-converted form, and said refraction signal detecting means includes filter means for excluding from its output substantially all other signals except said down-converted signal from said second IF channel corresponding to said second carrier, to produce an output signal comprising sunstantially only said refraction signal.
Claim 14
Dependent Claim
79 words
Apparatus according to claim 10 including a network of frequency multipliers and dividers arranged to operate from said first stable oscillator output to produce said second and third signals, as different multiples of said first oscillator output, and in which said Doppler detecting means includes a first Doppler detector operating from said second oscillator output and said controlled frequency oscillator output and a second Doppler detector and operating from said third oscillator output and said first Doppler detector output.
Claim 15
Dependent Claim
45 words
Apparatus according to claim 11 in which the frequency relationships among said first, second and third stable oscillator signals are predetermined to provide appropriate phase detection references and predetermined frequency spacing of the first and second IF signals corresponding to said first and second carriers.
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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |