Optimization of circuit parameters for the vortex flow transistor

The Vortex Flow Transistor (VFT) has been proposed as a superconducting amplifying device. Useful circuits at microwave frequencies may be achievable using distributed amplifier concepts. However, realization of these circuits depends on obtaining a circuit model for this device and then characterizing and optimizing the elements that make up this model. In order to study these elements, a group of devices with various geometric differences were fabricated with Nb-Pb technology. Initial results of a study of the low and high frequency properties of the transresistance, output resistance, feedthrough capacitance, and input inductance of the VFT are presented.