Patent US5373265A successfully refreshed from Google Patents.
US5373265A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modulator having oscillator for generating IF and RF signals by division and up-conversion
Assignee: AT&T Inc
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Filing: 1993-07-06
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Granted: 1994-12-13
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Expires: 2013-07-06
Abstract
Abstract Apparatus and method for effecting single sideband suppressed carrier modulation suitable for small, hand-held, high-frequency cellular radio transmitters such as those used at 900 mHz. A local oscillator generates a signal at 0.8 the frequency of the desired carrier. The generated frequency is counted down to produce an IF that is 0.2 the frequency of the desired carrier and the IF is mixed with the baseband signal to produce a modulated IF. The modulated IF is then mixed with the first generated signal to generate the modulated carrier signal. Advantageously, all of the foregoing components can be provided on the same integrated circuit chip.
Inventors
- 👤 Paul C. Davis
- 👤 Irving G. Post
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:20
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/38; H03C3/40; H03D; H03D7/00; H03D7/16; H03D7/165; H03C1/00; H03C1/52; H03C1/60; H03C2200/00; H03C2200/0037; H03C2200/007
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
82 words
A method of modulating a carrier with a baseband signal, comprising the steps of: a. synthesizing a first frequency which is 80 percent of the frequency of said carrier, b. dividing said first frequency to provide an intermediate frequency that is 20 percent of said carrier frequency; c. modulating said intermediate frequency with said baseband signal to produce a modulated intermediate frequency signal, and d. mixing said modulated intermediate frequency signal with said synthesized first frequency to produce a modulated carrier signal.
Claim 2
Independent Claim
82 words
A method of modulating a carrier with a baseband signal, comprising the steps of: a. synthesizing a first frequency which is 80 percent of the frequency of said carrier, b. dividing said first frequency to provide an intermediate frequency that is 20 percent of said carrier frequency; c. modulating said intermediate frequency with said baseband signal to produce a modulated intermediate frequency signal, and d. mixing said modulated intermediate frequency signal with said synthesized first frequency to produce a modulated carrier signal.
Claim 3
Dependent Claim
24 words
The method of modulating according to claim 1 wherein said signal for modulating said intermediate frequency is in quadrature phase with said intermediate frequency.
Claim 4
Dependent Claim
14 words
The method of modulating according to claim 1 wherein said carrier frequency is suppressed.
Claim 5
Dependent Claim
20 words
The method of modulating according to claim 1 wherein said modulated intermediate frequency signal comprises a pair of sideband signals.
Claim 6
Dependent Claim
16 words
The method of modulating according to claim 4 wherein one of said sideband signals is suppressed.
Claim 7
Dependent Claim
16 words
A method of modulating according to claim 1 wherein said carrier frequency is approximately 900 mHz.
Claim 8
Dependent Claim
87 words
Circuitry for modulating a carrier with a baseband frequency, comprising, a. means for generating a first frequency which is 80 percent of the desired carrier frequency; b. means for producing an intermediate frequency from said frequency generated by said generating means that is one-fifth the frequency of said carrier; c. means for modulating said intermediate frequency with said baseband signal to produce a modulated intermediate frequency signal; and d. means for mixing said modulated intermediate frequency signal with said first frequency to produce a modulated carrier signal.
Claim 9
Dependent Claim
87 words
Circuitry for modulating a carrier with a baseband frequency, comprising, a. means for generating a first frequency which is 80 percent of the desired carrier frequency; b. means for producing an intermediate frequency from said frequency generated by said generating means that is one-fifth the frequency of said carrier; c. means for modulating said intermediate frequency with said baseband signal to produce a modulated intermediate frequency signal; and d. means for mixing said modulated intermediate frequency signal with said first frequency to produce a modulated carrier signal.
Claim 10
Independent Claim
82 words
A method of modulating a carrier with a baseband signal, comprising the steps of: a. synthesizing a first frequency which is M percent of the frequency of said carrier, b. dividing said first frequency to provide an intermediate frequency that is 100--M percent of said carrier frequency; c. modulating said intermediate frequency with said baseband signal to produce a modulated intermediate frequency signal, and d. mixing said modulated intermediate frequency signal with said synthesized first frequency to produce a modulated carrier signal.
Claim 11
Independent Claim
82 words
A method of modulating a carrier with a baseband signal, comprising the steps of: a. synthesizing a first frequency which is M percent of the frequency of said carrier, b. dividing said first frequency to provide an intermediate frequency that is 100--M percent of said carrier frequency; c. modulating said intermediate frequency with said baseband signal to produce a modulated intermediate frequency signal, and d. mixing said modulated intermediate frequency signal with said synthesized first frequency to produce a modulated carrier signal.
Claim 12
Dependent Claim
18 words
A method of modulating a carrier with a baseband signal according to claim 8 wherein M is 80.
References Cited (Backward Citations)
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