Document Type and Number:
Japanese Patent JPS4012811
Kind Code:
B1
Abstract:
1,067,756. Superconductor circuits. RADIO CORPORATION OF AMERICA. Oct. 25, 1963, No. 42271/63. Heading H3B. A ryotron, i.e. a cryoelectric controllable inductor, is used as the variable inductance in various variable reactance amplifiers. By varying the magnetic field penetration depth X of the control ground plane of the ryotron by varying the state of the ground plane between superconducting and normal states the amount of shielding afforded by the ground plane is varied between wide limits and hence the inductance of a conductive controlled element of the ryotron is also varied over wide limits. A parametric amplifier employing such a device is as shown in Fig. 2 and Fig. 1 (not shown). The control ground plane of a ryotron is biased by battery 50 to still be in a superconducting state, point (B), Fig. 3 (not shown), and acting as a perfect shield to controlled element 34, driven by current source 421 generating a current at frequency F 2 , pump frequency. An input signal of frequency F 1 from source 381 is applied to the control ground plane and is sufficient to produce a great increase in #, and a corresponding increase in the inductance of the controlled element 34. Load RL is connected in shunt with idler circuit 481 tuned to a frequency F 3 where F 3 = F 1 + F 2 or F 2 - F 1 depending on whether the amplifier is an up or down converter. The pump sources 38, 42 may be interchanged. In the embodiment of Fig. 4 (not shown) the ryotron has one control ground plane and two controlled elements (variable inductances), one controlled element being connected to a first idler circuit tuned to a frequency F 2 + F 1 and the second controlled element connected to a second idler circuit tuned to a frequency F 2 - F 1 . In the circuit of Fig. 5 (not shown) several input signals are applied to the control ground plane and several input signals applied to the controlled element, a number of idler circuits of different frequencies being also supplied. The control ground plane may be driven into and out of the high # state by means of modulated infra-red rays, Fig. 6 (not shown). The circuit of Fig. 7 (not shown) shows a cascaded amplifier comprising two ryotrons (101), (103) the load of ryotron (101) comprising the control ground plane of ryotron (103) which is driven by a signal of frequency F 3 = F 1 + F 2 . Since the controlled element (107) of ryotron (103) is driven by a pump source of frequency F 2 and the idler circuit is tuned to F 1 = F 3 - F 2 the load R L receives an amplified signal at frequency F 1 .
Application Number:
JP6109963A
Publication Date:
June 22, 1965
Filing Date:
November 13, 1963
Export Citation:
International Classes:
G11C11/44; H03F7/02