US3826995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency generators
Assignee: BAE Systems Electronics Ltd
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Filing: 1972-10-30
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Granted: 1974-07-30
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Expires: 1992-10-30
Abstract
Abstract A frequency generator produces a comb-like spectrum of frequencies, each of the frequencies being derived from a single standard frequency. A relatively small number of predetermined frequencies are derived directly from the standard frequency and arranged in groups. Thereafter all frequencies in each group are mixed with all frequencies in all other groups to produce the required comb-like frequency spectrum. The invention permits a large number of frequencies to be accurately derived from a single frequency in a practicable and economical manner.
Inventors
- 👤 W Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:42
CPC Classifications
H; H03; H03B; H03B21/00; H03B21/01; H03B21/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
218 words
A frequency generator system for simultaneously producing a large number of output signals each of a different frequency and cumulatively defining a comb-like spectrum of frequencies, comprising in combination: means for generating a first group of different frequencies and including a stable oscillator; means for generating from said first group of frequencies a plurality of further groups of different frequencies, the sum of said frequencies of said first and said further groups of frequencies being small in relation to said large number of output signals; a plurality of mixing channels each including a first mixer and a plurality of serially connected second mixers, said first mixer of each channel being connected to a pair of frequencies of said first group and said second mixers of each channel being connected to a set of frequencies where each set comprises frequencies selected from each further group; and and of said frequencies being related to produce said comb-like spectrum of frequencies from said mixing channels in which the number of frequencies in said spectrum is large compared to said sum of frequencies; each mixing channel also including a controllable phase shifter in an input path of the first mixer and controlled in dependence on the phase of such mixing channel relative to a reference signal from the first group of frequencies.
Claim 2
Dependent Claim
218 words
A frequency generator system for simultaneously producing a large number of output signals each of a different frequency and cumulatively defining a comb-like spectrum of frequencies, comprising in combination: means for generating a first group of different frequencies and including a stable oscillator; means for generating from said first group of frequencies a plurality of further groups of different frequencies, the sum of said frequencies of said first and said further groups of frequencies being small in relation to said large number of output signals; a plurality of mixing channels each including a first mixer and a plurality of serially connected second mixers, said first mixer of each channel being connected to a pair of frequencies of said first group and said second mixers of each channel being connected to a set of frequencies where each set comprises frequencies selected from each further group; and and of said frequencies being related to produce said comb-like spectrum of frequencies from said mixing channels in which the number of frequencies in said spectrum is large compared to said sum of frequencies; each mixing channel also including a controllable phase shifter in an input path of the first mixer and controlled in dependence on the phase of such mixing channel relative to a reference signal from the first group of frequencies.
Claim 3
Dependent Claim
45 words
A generator as claimed in claim 1 wherein each first mixer is followed by a first band-pass filter, and said second mixers are each followed by a band-pass filter, the number of second mixers being equal to the number of said different groups of frequencies.
Claim 4
Dependent Claim
29 words
A generator as claimed in claim 1 wherein a controllable-gain amplifier is present in the said path between the said first pass-band filter and the plurality of second mixers.
Claim 5
Dependent Claim
54 words
A generator as claimed in claim 3 wherein the amplitude of an output frequency resulting from the said plurality of second mixers is compared with an amplitude reference signal and the gain of the controllable-gain amplifier controlled in dependence on the result of this comparison to provide an output frequency having a desired amplitude.
Claim 6
Dependent Claim
40 words
A generator as claimed in claim 1 wherein the said channels are arranged to produce a comb-like spectrum of frequencies in which the frequencies are regularly spaced; the frequency difference between all pairs of adjacent frequency values being the same.
Claim 7
Dependent Claim
118 words
A generator as claimed in claim 5 wherein the frequency output of each channel in a pair of channels providing outputs having adjacent frequency values is coupled to a mixer, this mixer being arranged to provide a difference frequency equal to the difference in frequencies applied to it, and said difference frequency being applied to a further mixer to which is also applied a reference frequency equal to the nominal value of the difference frequency, said further mixer being arranged to provide an output signal representative of the phase difference between the two frequencies applied to it, and said representative signal being used to control the said controllable phase shifter so as to reduce the said phase difference.
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) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |