An electrical interconnect provides a path between cryogenic or cryocooled
circuitry and ambient temperatures. As a system, a cryocable 10 is
combined with a trough-line contact or transition 20. In the preferred
embodiment, the cryocable 10 comprises a conductor 11 disposed adjacent an
insulator 12 which is in turn disposed adjacent another conductor 13. The
components are sized so as to balance heat load through the cryocable 10
with the insertion loss. In the most preferred embodiment, a coaxial
cryocable 10 has a center conductor 11 surrounded by a dielectric 12 (e.g.
Teflon.TM.) surrounded by an outer conductor 13 which has a thickness
between about 6 and 20 microns. The heat load is preferably less than one
Watt, and most preferably less than one tenth of a Watt, with an insertion
loss less than one decibel. In another aspect of the invention, a
trough-line contact or transition 20 is provided in which the center
conductor 11 is partially enveloped by dielectric 12 to form a relatively
flat portion 28. The preferred overall geometry of the preferred
embodiment of the cable is generally cylindrical, although other
geometries are possible (e.g., stripline, microstrip, coplanar or slotline
geometries). In a further aspect of the present invention, a push-on
connector 120 is provided to facilitate connection and disconnection of
the cryocable from an HTS circuit and/or a mating feedthrough 124.