A modified superconducting current injection transistor and distributed amplifier design

Conference · Wed Mar 01 04:00:00 EST 1989 · IEEE Trans. Magn.; (United States)

OSTI ID:6044093

McGinnis, D P; Beyer, J B; Nordman, J E

The authors have modified the design of the Superconducting Current Injection Transistor (Super-CIT) for use in a distributed amplifier. The Super-CIT consists of a resistively damped long Josephson junction in which the maximum Josephson current is modulated by the magnetic field produced by current in a control line. The maximum frequency of operation of this device is limited by the transit time of a fluxon through the junction. Thus, transit tie cutoff frequencies can be as high as several hundred gigahertz. The device is modified by dc decoupling the control line from the Josepson junction so that the Super-CIT can be embedded in a distributed amplifier configuration. This distributed amplifier design, which is a hybrid of the Field Effect Transistor and the Superconducting Vortex Flow Transistor distributed amplifier configurations, is used to raise the input impedance and the power gain of the amplifier over a wide bandwidth. In addition, the small signal current gain of the device can be increased by biasing the Josephson junction in an asymmetric configuration. A simulation using practical values results in an amplifier with an input impedance of 6.5 ohms using only four devices that produces 15 dB of gain into a 2.5 ohm load over a bandwidth of 90 GHz with very little reverse gain.

• Research Organization: Fermi National Accelerator Lab., Batavia, IL (US); Dept. of Electrical and Computer Engineering, Univ. of Wisconsin-Madison, Madison, WI (US)
• OSTI ID: 6044093
• Report Number(s): CONF-880812-
• Conference Information: Journal Name: IEEE Trans. Magn.; (United States) Journal Volume: 25:2
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFIERS
CONFIGURATION
DESIGN
ELECTRIC IMPEDANCE
ELECTRONIC EQUIPMENT
EQUIPMENT
FLUID FLOW
FREQUENCY MODULATION
IMPEDANCE
JOSEPHSON JUNCTIONS
JUNCTIONS
MAGNETIC FIELDS
MODULATION
SEMICONDUCTOR DEVICES
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS
TRANSISTORS
VORTEX FLOW