US3913027A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High gain, large bandwidth amplifier based on the josephson effect
Assignee: International Business Machines Corp
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Filing: 1974-02-11
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Granted: 1975-10-14
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Expires: 1994-02-11
Abstract
Abstract A wide band linear amplifier comprising first and second heavily damped Josephson devices and associated superconducting circuitry. Each Josephson device has a parallel path with a load resistor connected thereto. The parallel path connected to the first Josephson device is positioned to operate as a control current path for the second Josephson device. Both Josephson devices are operated on linear portions of their respective gain curves. The output current through the second load resistance is a linear amplification of the input current; the latter being applied as control current to the first Josephson device.
Inventors
- 👤 Hans Helmut Zappe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:45
CPC Classifications
H; H03; H03F; H03F19/00; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/855
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
195 words
A wide band linear amplifier comprising, a. first and second Josephson devices, each having a gain curve which is linear over a finite range of control current, and each being heavily damped and having damping resistances R1 and R2 respectively, b. a first superconducting circuit including said first Josephson device and further comprising a super-conducting path having a load resistance RL1 therein in parallel circuit arrangement with said first Josephson device, and further superconductors for carrying a gating current Ig1 to said parallel arrangement, c. a second superconducting circuit including said second Josephson device and further comprising a superconducting path having a load resistance RL2 therein in parallel circuit arrangement with said second Josephson device, and further superconductors for carrying a gating current Ig2 to said parallel arrangement, d. said superconducting path having load resistance RL1 therein being positioned so that a portion thereof overlies said second Josephson device in a direction parallel to the direction of current flow through said second Josephson device, and e. an input control current superconductor for carrying input control current positioned to overlie said first Josephson device parallel to the direction of current flow through said first Josephson device.
Claim 2
Dependent Claim
195 words
A wide band linear amplifier comprising, a. first and second Josephson devices, each having a gain curve which is linear over a finite range of control current, and each being heavily damped and having damping resistances R1 and R2 respectively, b. a first superconducting circuit including said first Josephson device and further comprising a super-conducting path having a load resistance RL1 therein in parallel circuit arrangement with said first Josephson device, and further superconductors for carrying a gating current Ig1 to said parallel arrangement, c. a second superconducting circuit including said second Josephson device and further comprising a superconducting path having a load resistance RL2 therein in parallel circuit arrangement with said second Josephson device, and further superconductors for carrying a gating current Ig2 to said parallel arrangement, d. said superconducting path having load resistance RL1 therein being positioned so that a portion thereof overlies said second Josephson device in a direction parallel to the direction of current flow through said second Josephson device, and e. an input control current superconductor for carrying input control current positioned to overlie said first Josephson device parallel to the direction of current flow through said first Josephson device.
Claim 3
Dependent Claim
20 words
A wide band linear amplifier as claimed in claim 1 wherein the gating currents Ig1 and Ig2 satisfy the condition,
Claim 4
Dependent Claim
54 words
A wide band linear amplifier as claimed in claim 2 wherein each of said first and second Josephson devices satisfies the equation, CR2Im< o/2 pi , where, C is the device capacitance, R is the total damping resistance across the device, Im is the Josephson threshold current, and o is the magnetic flux quantum.
Claim 5
Dependent Claim
49 words
A wide band linear amplifier as claimed in claim 3 further comprising separate bias control current superconducting means for carrying a bias control current for said second Josephson device, and means overlying said second Josephson device in a direction parallel to the current direction through said second Josephson device.
Claim 6
Dependent Claim
47 words
A wide band linear amplifier as claimed in claim 4 wherein said parallel superconducting paths having said load resistances RL1 and RL2 therein, respectively, further include ultra high frequency filtering means for removing Josephson Oscillations from the load current flowing through said load resistances RL1 and RL2.
Claim 7
Independent Claim
164 words
An apparatus comprising: first and second devices in which Josephson current can flow, said devices exhibiting substantially no hysteresis when switched, each device having a gain curve which is linear over a finite range of control current and each of which is heavily damped by an external resistance, said devices having first and second total damping resistances R1 and R2 respectively, a first circuit including said first device and having a load resistance RL1 therein, said first circuit being connected to said first device, a source of a gating current Ig1 for providing current through said first device, a second circuit including said second device and having a load resistance RL2 therein, said second circuit being connected to said second device, a source of a gating current Ig2 to said second device, said first circuit connected to said first device being positioned so that current through said first circuit controls said second device and, means for providing control signals for regulating said first device.
Claim 8
Independent Claim
164 words
An apparatus comprising: first and second devices in which Josephson current can flow, said devices exhibiting substantially no hysteresis when switched, each device having a gain curve which is linear over a finite range of control current and each of which is heavily damped by an external resistance, said devices having first and second total damping resistances R1 and R2 respectively, a first circuit including said first device and having a load resistance RL1 therein, said first circuit being connected to said first device, a source of a gating current Ig1 for providing current through said first device, a second circuit including said second device and having a load resistance RL2 therein, said second circuit being connected to said second device, a source of a gating current Ig2 to said second device, said first circuit connected to said first device being positioned so that current through said first circuit controls said second device and, means for providing control signals for regulating said first device.
Claim 9
Dependent Claim
34 words
The apparatus of claim 6, wherein the gating currents Ig1 and Ig2 satisfy the condition Ig2/Ig1 about K(R1/RL1), where K is the slope of a portion of the gain curve of said second device.
Claim 10
Dependent Claim
20 words
The apparatus of claim 7, wherein said first and second devices are damped by the resistances RL1 and RL2, respectively.
Claim 11
Dependent Claim
52 words
The apparatus of claim 8, where said first and second devices satisfy the inequality. CR2Im < Phi o/2 pi , where C is the device capacitance, R is the total damping resistance across each device, Im is the maximum current through each tunnel device, and Phi o is the magnetic flux quantum.
Claim 12
Dependent Claim
30 words
The apparatus of claim 6, wherein said first and second circuits include filtering means for removing Josephson oscillations from the currents which flow through said load resistances RL1 and RL2.
Claim 13
Independent Claim
141 words
An apparatus comprising: a first device capable of supporting Josephson current therethrough, said first device being connected to a first circuit having a resistance RL1 which heavily damps said first device wherein the total damping resistance of said first device is R1, a second device capable of supporting Josephson current therethrough, said second device being connected to a second circuit having a resistance RL2 which heavily damps said second device, means for providing electrical currents Ig1 through said first device and Ig2 through said second device, where the ratio Ig2/Ig1 bears a linear relationship to the ratio R1/RL1, control means for switching said first device to transfer at least a portion of said current Ig1 into said first circuit, wherein said first circuit is positioned with respect to said second device that current in said first circuit controls said second device.
Claim 14
Independent Claim
141 words
An apparatus comprising: a first device capable of supporting Josephson current therethrough, said first device being connected to a first circuit having a resistance RL1 which heavily damps said first device wherein the total damping resistance of said first device is R1, a second device capable of supporting Josephson current therethrough, said second device being connected to a second circuit having a resistance RL2 which heavily damps said second device, means for providing electrical currents Ig1 through said first device and Ig2 through said second device, where the ratio Ig2/Ig1 bears a linear relationship to the ratio R1/RL1, control means for switching said first device to transfer at least a portion of said current Ig1 into said first circuit, wherein said first circuit is positioned with respect to said second device that current in said first circuit controls said second device.
Claim 15
Dependent Claim
36 words
The apparatus of claim 11, where said first device has a maximum Josephson current Im1 and said control means carries a current Ic1, where Im1 is a linear function of Ic1 over a range of Ic1.
Claim 16
Dependent Claim
35 words
The apparatus of claim 12, where said second device has a maximum Josephson current Im2 which is linearly related to the magnitude of said control magnetic field over a range of said control magnetic field.
Claim 17
Dependent Claim
23 words
The apparatus of claim 13, further including means for filtering Josephson oscillations from the currents flowing through said load resistances RL1 and RL2.
Claim 18
Independent Claim
76 words
An apparatus comprising: a first device capable of supporting Josephson tunneling current therethrough said first device being connected to a first circuit having a resistance RL1, a second device capable of supporting Josephson tunneling current therethrough said second device being electrically connected to said first circuit and to a second circuit having a resistance RL2 associated therewith, wherein said first and second devices exhibit substantially no hysteresis when switched, and control means for switching said devices.
Claim 19
Independent Claim
76 words
An apparatus comprising: a first device capable of supporting Josephson tunneling current therethrough said first device being connected to a first circuit having a resistance RL1, a second device capable of supporting Josephson tunneling current therethrough said second device being electrically connected to said first circuit and to a second circuit having a resistance RL2 associated therewith, wherein said first and second devices exhibit substantially no hysteresis when switched, and control means for switching said devices.
Claim 20
Dependent Claim
23 words
The apparatus of claim 15, where said resistance RL1 heavily damps said first device and said resistance RL2 heavily damps said second device.
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) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |