US3961264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear frequency converter with gain independent of circuit parameters
Assignee: Hekimian Laboratories Inc
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Filing: 1974-05-02
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Granted: 1976-06-01
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Expires: 1994-05-02
Abstract
Abstract A frequency converter circuit includes an input voltage-to-current converter which delivers signal current to a tuned IF circuit via a current steering circuit controlled by a local oscillator. In a preferred embodiment voltage-to-current conversion is effected without introducing unwanted harmonics by a double-gate MOSFET. Current steering is performed by a pair of push-pull connected transistors alternately driven into saturation by the local oscillator so that they alternately deliver signal current to the tank circuit in opposite senses. A current-limited diode clamps the output signal level in response to high input current levels to prevent over-driving an output filter.
Inventors
- 👤 Norris C. Hekimian
- 👤 Walter Mack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:03
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/16; H03D7/12; H03D7/125; H03D7/14; H03D7/161; H03D7/165
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
150 words
A frequency converter circuit responsive to a local oscillator signal and an input voltage signal for providing an output signal at a predetermined frequency, said circuit comprising: active means for converting said input voltage signal to a signal current having an amplitude proportional to the input voltage; circuit means tuned to said predetermined frequency; current steering means responsive to said local oscillator signal for alternately conducting said signal current via two paths to said circuits means; output means operable over a range of relatively low applied signal amplitudes; means for applying said output signal to said output means at an amplitude which is a function of the current conducted to said circuit means by said steering means; and current limiting diode means for limiting the maximum possible current through said steering means to a level which corresponds to an output signal amplitude residing within said range of relatively low amplitudes.
Claim 2
Dependent Claim
150 words
A frequency converter circuit responsive to a local oscillator signal and an input voltage signal for providing an output signal at a predetermined frequency, said circuit comprising: active means for converting said input voltage signal to a signal current having an amplitude proportional to the input voltage; circuit means tuned to said predetermined frequency; current steering means responsive to said local oscillator signal for alternately conducting said signal current via two paths to said circuits means; output means operable over a range of relatively low applied signal amplitudes; means for applying said output signal to said output means at an amplitude which is a function of the current conducted to said circuit means by said steering means; and current limiting diode means for limiting the maximum possible current through said steering means to a level which corresponds to an output signal amplitude residing within said range of relatively low amplitudes.
Claim 3
Dependent Claim
18 words
The circuit according to claim 1 further comprising degenerative feedback means for linearizing operation of said active means.
Claim 4
Dependent Claim
121 words
A frequency converter circuit responsive to a local oscillator signal and an input voltage signal for providing an output signal at a predetermined frequency, said circuit comprising: active means for converting said input voltage signal to a signal current having an amplitude proportional to the input voltage; circuit means tuned to said predetermined frequency; current steering means for alternately conducting said signal current via two paths to said circuit means; and means for limiting diode current to a predetermined amplitude through said current steering means; wherein said active means comprises a double-gate MOSFET having a source-drain current path, and wherein said input voltage is applied to one gate of said MOSFET and said signal current flows in said source-drain current path.
Claim 5
Dependent Claim
121 words
A frequency converter circuit responsive to a local oscillator signal and an input voltage signal for providing an output signal at a predetermined frequency, said circuit comprising: active means for converting said input voltage signal to a signal current having an amplitude proportional to the input voltage; circuit means tuned to said predetermined frequency; current steering means for alternately conducting said signal current via two paths to said circuit means; and means for limiting diode current to a predetermined amplitude through said current steering means; wherein said active means comprises a double-gate MOSFET having a source-drain current path, and wherein said input voltage is applied to one gate of said MOSFET and said signal current flows in said source-drain current path.
Claim 6
Dependent Claim
56 words
The circuit according to claim 3 wherein said current steering means comprises a pair of push-pull connected bipolar transistors having emitters connected together to receive said signal current, said transistors having a base wherein at least one base is connected to receive said local oscillator signal, said transistors additionally including collectors connected to said circuit means.
Claim 7
Dependent Claim
24 words
The circuit according to claim 4 wherein said current-limiting diode means is connected in series with said circuit means and each of said collectors.
Claim 8
Dependent Claim
20 words
The circuit according to claim 5 further comprising a capacitor coupling said signal current from said drain to said emitters.
Claim 9
Dependent Claim
135 words
A frequency converter circuit responsive to a local oscillator signal and an input voltage signal for providing an output signal at a predetermined frequency, said circuit comprising: active means for converting said input voltage signal to a signal current having an amplitude proportional to the input voltage; circuit means tuned to said predetermined frequency; current steering means for alternately conducting said signal current via two paths to said circuits means; and means for limiting diode current to a predetermined amplitude through said current steering means; wherein said current steering means comprises a pair of push-pull connected bipolar transistors having emitters connected together to receive said signal current, said transistors having a base wherein at least one base is connected to receive said local oscillator signal, said transistors additionally including collectors connected to said circuit means.
Claim 10
Dependent Claim
135 words
A frequency converter circuit responsive to a local oscillator signal and an input voltage signal for providing an output signal at a predetermined frequency, said circuit comprising: active means for converting said input voltage signal to a signal current having an amplitude proportional to the input voltage; circuit means tuned to said predetermined frequency; current steering means for alternately conducting said signal current via two paths to said circuits means; and means for limiting diode current to a predetermined amplitude through said current steering means; wherein said current steering means comprises a pair of push-pull connected bipolar transistors having emitters connected together to receive said signal current, said transistors having a base wherein at least one base is connected to receive said local oscillator signal, said transistors additionally including collectors connected to said circuit means.
Claim 11
Dependent Claim
27 words
The circuit according to claim 7 wherein said means for limiting includes a current-limiting diode connected in series with said circuit means and each of said collectors.
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) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |