Thermal Modulation of Superconducting Inductors
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
Increasing the superconducting penetration depth, by sandwiching a heater (normal metal film) between a superconducting stripline and its ground plane, increases the inductance per unit length and permits thermal adjustment or modulation of the inductance. The inductance per unit length (neglecting fringing) of a superconducting stripline over the groundplane is given by: where 1 is the width of the line, t is the separation between the groundplane and the line, g1 is the superconducting penetration depth of the groundplane, and g2 is the penetration depth of the stripline. (The superconductors are assumed to be thick compared to g1 and g2.) If the temperature is increased, the energy gaps to the stripline and groundplane decrease, leading to an increase in the penetration depths and an increase in L.