US4975658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency amplifier circuit with noise figure improvement
Assignee: Pioneer Corp
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Filing: 1989-01-17
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Granted: 1990-12-04
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Expires: 2009-01-17
Abstract
Abstract A high frequency, negative feedback amplifier is coupled at its input to an inductance network which together with the input capacitance of the negative feedback amplifier forms a resonance circuit. The resonance frequency of the resonance circuit is set within the desired reception band of the amplifier, to thereby form a band pass filter having a pass band corresponding to the desired reception band. The resonance circuit assures only a real input to the amplifier thereby reducing the input noise attributable to the input source.
Inventors
- 👤 Masami Takayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:44
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/34; H03F1/347; H03F3/00; H03F3/189; H03F3/19; H03F3/193; H03F3/1935
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
87 words
A high frequency amplifier circuit comprising: a negative feedback amplifier circuit for high frequency amplifying a signal received through an antenna; and a network connected to an input of said negative feedback amplifier circuit, said network having no capacitance so that said network consitutes a resonance circuit together with only an input capacitance in said negative feedback amplifier circuit, the resonance frequency of said resonance circuit being set within a reception band to form a bandpass filter having a pass band substantially corresponding to said reception band.
Claim 2
Dependent Claim
87 words
A high frequency amplifier circuit comprising: a negative feedback amplifier circuit for high frequency amplifying a signal received through an antenna; and a network connected to an input of said negative feedback amplifier circuit, said network having no capacitance so that said network consitutes a resonance circuit together with only an input capacitance in said negative feedback amplifier circuit, the resonance frequency of said resonance circuit being set within a reception band to form a bandpass filter having a pass band substantially corresponding to said reception band.
Claim 3
Dependent Claim
83 words
An amplifier circuit comprising: a negative feedback amplifier circuit for receiving and amplifying an input signal; and a network connected to an input of said negative feedback amplifier circuit, said network having no capacitance so that said network constitutes a resonance circuit together with only an input capacitance included in said negative feedback amplifier, the resonance frequency of said resonance circuit being set within a reception band to form a band pass filter having a pass band substantially corresponding to said reception band.
Claim 4
Dependent Claim
83 words
An amplifier circuit comprising: a negative feedback amplifier circuit for receiving and amplifying an input signal; and a network connected to an input of said negative feedback amplifier circuit, said network having no capacitance so that said network constitutes a resonance circuit together with only an input capacitance included in said negative feedback amplifier, the resonance frequency of said resonance circuit being set within a reception band to form a band pass filter having a pass band substantially corresponding to said reception band.
Claim 5
Dependent Claim
20 words
An amplifier circuit as claimed in claim 2 wherein said negative feedback amplifier circuit is a high frequency amplifier circuit.
Claim 6
Dependent Claim
21 words
An amplifier circuit as claimed in claim 2 wherein said negative feedback amplifier circuit is a medium band frequency amplifier circuit.
Claim 7
Dependent Claim
27 words
An amplifier circuit as claimed in claim 2 further including at least one additional amplifier circuit cascade connected to the output of said negative feedback amplifier circuit.
Claim 8
Dependent Claim
31 words
An amplifier circuit as claimed in claim 1, wherein said network is comprised of an inductance serially connected between a signal input terminal and the input of said negative feedback amplifier.
Claim 9
Dependent Claim
17 words
An amplifier circuit as claimed in claim 6, further including an antenna connected to said input terminal.
Claim 10
Dependent Claim
31 words
An amplifier circuit as claimed in claim 2, wherein said network is comprised of an inductance serially connected between a signal input terminal and the input of said negative feedback amplifier.
Claim 11
Dependent Claim
134 words
An amplifier circuit comprising: a negative feedback amplifier circuit for receiving and amplifying an input signal; and a network connected to an input of siad negative feedback amplifier circuit, said network having no capacitance so that said network constitutes a resonance circuit together with only an input capacitance included in said negative feedback amplifier, the resonance frequency of said resonance circuit being set within a reception band to form a band pass filter having a pass band substantially corresponding to said reception band, wherein said negative feedback amplifier circuit comprises a field effect transistor having a gate, a drain and a source, the gate of said field effect transistor receiving said input signal, and a negative feedback transformer having a first coil connected to said drain and a second coil connected to said source.
Claim 12
Dependent Claim
134 words
An amplifier circuit comprising: a negative feedback amplifier circuit for receiving and amplifying an input signal; and a network connected to an input of siad negative feedback amplifier circuit, said network having no capacitance so that said network constitutes a resonance circuit together with only an input capacitance included in said negative feedback amplifier, the resonance frequency of said resonance circuit being set within a reception band to form a band pass filter having a pass band substantially corresponding to said reception band, wherein said negative feedback amplifier circuit comprises a field effect transistor having a gate, a drain and a source, the gate of said field effect transistor receiving said input signal, and a negative feedback transformer having a first coil connected to said drain and a second coil connected to said source.
Claim 13
Dependent Claim
52 words
An amplifier circuit as claimed in claim 9, further including means for operating said field effect transistor such that the drain current, I D , is substantially equal to the steady-state drain current I DSS , to thereby maximize the transistor transconductance, g m , whereby the transistor thermal noise is minimized.
References Cited (Backward Citations)
US3810256A
Cited
JPS54118758A
Cited
DE2953382C1
Cited
DE3407020A1
Cited
US4590434A
Cited
SU1224960A1
Cited
US4749759A
Cited
FR2605817A1
Cited
US4774477A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |