US3775708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave signal attenuator
Assignee: Anaren Microwave Inc
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Filing: 1973-01-12
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Granted: 1973-11-27
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Expires: 1993-01-12
Abstract
Abstract A microwave signal attenuator includes at least two diodes shunting to ground points separated by a quarter of a centerfrequency wavelength on a transmission line. At a quarter centerfrequency wavelength from each diode toward the input and output ports respectively, are connected first and second circuits respectively, comprising an impedance and a diode in series. Bias current is fed via each circuit, the transmission line and the two diodes to ground to controllably vary the resistance of the diodes in accordance with the desired attenuation.
Inventors
- 👤 T Sly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:18
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/24; H03H7/25; H03H7/253; H03H7/255
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
271 words
A microwave signal attenuator for attenuating signals having a given center-frequency comprising a microwave signal conductor with a given characteristic impedance and having an input port at one end and a signal output port at the other end, at least first and second diodes, said first diode connecting a first point on said microwave signal conductor to ground, said second diode connecting a second point on said microwave signal conductor to ground, said first and second points being separated by an odd number of quarter center-frequency wavelengths, a first circuit including an impedance having a resistive component with a value at said center-frequency substantially equal to said characteristic impedance and a third diode connected in series, one end of said first circuit being connected to a third point on said microwave signal conductor which is between said input port and said first point and displaced from said first point by an odd number of quarter center-frequency wavelengths, a second circuit including an impedance having a resistive component with a value at said center-frequency substantially equal to said characteristic impedance and a fourth diode connected in series, one end of said second circuit being connected to a fourth point on said microwave signal conductor which is between said output port and said second point and displaced from said second point by an odd number of quarter center-frequency wavelengths, and bias means for applying a current to said first circuit so that the same cuurrent flows through said third and first diodes, and for applying a current to said second circuit so that the same current flows through said fourth and second diodes.
Claim 2
Dependent Claim
271 words
A microwave signal attenuator for attenuating signals having a given center-frequency comprising a microwave signal conductor with a given characteristic impedance and having an input port at one end and a signal output port at the other end, at least first and second diodes, said first diode connecting a first point on said microwave signal conductor to ground, said second diode connecting a second point on said microwave signal conductor to ground, said first and second points being separated by an odd number of quarter center-frequency wavelengths, a first circuit including an impedance having a resistive component with a value at said center-frequency substantially equal to said characteristic impedance and a third diode connected in series, one end of said first circuit being connected to a third point on said microwave signal conductor which is between said input port and said first point and displaced from said first point by an odd number of quarter center-frequency wavelengths, a second circuit including an impedance having a resistive component with a value at said center-frequency substantially equal to said characteristic impedance and a fourth diode connected in series, one end of said second circuit being connected to a fourth point on said microwave signal conductor which is between said output port and said second point and displaced from said second point by an odd number of quarter center-frequency wavelengths, and bias means for applying a current to said first circuit so that the same cuurrent flows through said third and first diodes, and for applying a current to said second circuit so that the same current flows through said fourth and second diodes.
Claim 3
Dependent Claim
59 words
The microwave signal attenuator of claim 1 wherein said first circuit comprises a first resistor, said third diode and a first reactive impedance connected in series and said second circuit comprises a second resistor, said fourth diode and a second reactive impedance connected in series, said resistors having values equal to the characteristic impedance of said microwave signal conductor.
Claim 4
Dependent Claim
40 words
The microwave signal attenuator of claim 2 wherein said first and second reactive impedances have values such that they are equal in magnitude and opposite in reactance function to the impedance between said third-and-first points and said fourth-and-second points, respectively.
Claim 5
Dependent Claim
46 words
The microwave signal attenuator of claim 3 wherein each of said first and second impedances is an open-ended transmission line having a characteristic impedance substantially equal to the characteristic impedance of said microwave signal and a length equal to an odd number of quarter center wavelengths.
Claim 6
Dependent Claim
55 words
The microwave signal attenuator of claim 3 wherein an end of each of said first and second resistors is connected to said third and fourth points, respectively, and said bias means is connected to the junction of said third diode and said first impedance and the junction of said fourth diode and said second impedance.
Claim 7
Dependent Claim
58 words
The microwave signal attenuator of claim 3 wherein all of said diodes have substantially the same shunt resistance-current characteristic and are polarized in the same direction to pass current from said bias means to ground whereby equal currents flow through all of said diodes so that all of said diodes have the same resistance at the center frequency.
Claim 8
Dependent Claim
55 words
The microwave signal attenuator of claim 6 wherein an end of each of said first and second resistors is connected to said third and fourth points, respectively, and said bias means is connected to the junction of said third diode and said first impedance and the junction of said fourth diode and said second impedance.
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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |