US3581210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rf t-pad low impedance coupling circuit attenuator with agc voltage control
Assignee: Individual
•
Filing: 1969-01-23
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Granted: 1971-05-25
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Expires: 1989-01-23
Abstract
Abstract An RF signal path variable attenuation circuit with common electrode connected diodes in the signal path and the diode interconnection connected through a transistor to ground. A voltage diode biasing circuit is also so connected in the circuit that the degree of voltage bias to conduction of the diodes is subject to variation through variable DC drain from the diode junction through the transistor along with, simultaneously, variable RF signal diversion to ground as controlled by AGC voltage variations applied at the transistor base.
Inventors
- 👤 Warren U Amfahr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:45
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0035; H03G1/0052; H03G3/00; H03G3/20; H03G3/30; H03G3/3052; H03G3/3057
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
174 words
A signal path variable attenuation circuit including: input signal coupling means, and output signal coupling means; first circuit means, and second circuit means interconnecting said input and output signal coupling means; said first circuit means having two resistance type diodes with a common electrode interconnection, and with RF signal diode impedance variable through a range as controlled by diode bias variation; a transistor having a base electrode connected to a variable voltage control source, a collector connected to said diode common electrode interconnection, and an emitter connected to ground for providing a variable high to low impedance RF path to ground from said diode common electrode interconnection through said transistor to ground; a first DC potential developing source connected between ground and the common junction of said collector and said diode common electrode interconnection; with impedance means connected between said second circuit means and ground; and a load resistor connected in series with said first DC potential developing source between ground and the common junction of said collector and said diode common electrode interconnection.
Claim 2
Dependent Claim
174 words
A signal path variable attenuation circuit including: input signal coupling means, and output signal coupling means; first circuit means, and second circuit means interconnecting said input and output signal coupling means; said first circuit means having two resistance type diodes with a common electrode interconnection, and with RF signal diode impedance variable through a range as controlled by diode bias variation; a transistor having a base electrode connected to a variable voltage control source, a collector connected to said diode common electrode interconnection, and an emitter connected to ground for providing a variable high to low impedance RF path to ground from said diode common electrode interconnection through said transistor to ground; a first DC potential developing source connected between ground and the common junction of said collector and said diode common electrode interconnection; with impedance means connected between said second circuit means and ground; and a load resistor connected in series with said first DC potential developing source between ground and the common junction of said collector and said diode common electrode interconnection.
Claim 3
Dependent Claim
20 words
The signal path variable attenuation circuit of claim 1 wherein, a resistor is connected between said transistor base and ground.
Claim 4
Dependent Claim
31 words
The signal path variable attenuation circuit of claim 1 wherein, said impedance means is a choke coil; and a second DC potential developing source connected between said choke coil and ground.
Claim 5
Dependent Claim
26 words
The signal path variable attenuation circuit of claim 3 wherein, said first DC potential developing source is connected through said second DC potential source to ground.
Claim 6
Dependent Claim
55 words
The signal path variable attenuation circuit of claim 4 wherein, an RF bypass capacitor is connected between said second circuit means and ground; and said load resistor is connected in series with said first DC potential developing source between said second DC potential developing source and the transistor collector common connection with the diode interconnection.
Claim 7
Dependent Claim
38 words
The signal path variable attenuation circuit of claim 5 wherein, said two resistance type diodes are common cathode connected diodes; said transistor is a PNP-type transistor; and said variable voltage control source is a variable negative voltage source.
Claim 8
Dependent Claim
40 words
The signal path variable attenuation circuit of claim 5 wherein, said two resistance type diodes are connected in common anode connected relation; said transistor is a NPN-type transistor; and said variable voltage control source is a variable positive voltage source.
Claim 9
Dependent Claim
37 words
AGC signal path variable attenuation circuit of claim 5 wherein said variable attenuation circuit is in the signal path of an RF signal receiver; and said variable voltage control source is an AGC circuit of the receiver.
Claim 10
Dependent Claim
26 words
The signal path variable attenuation circuit of claim 1 wherein, both said input signal coupling means and output signal coupling means are RF signal coupling transformers.
References Cited (Backward Citations)
US3428910A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |