Abstract: A superconductor on-chip microstrip line (2, 4) to off-chip microstrip line (7) transition of low characteristic impedance (15, 20, 22) is realized that obtains a bandwidth of 200 GHz for MCM application while employing solder bump (15, 17) technology to connect the chips (3, 5) to the off-chip microstrip and substrate (6). Circular openings (20, 22) through the respective ground plane layers (10 & 16) of the off-chip and on-chip microstrips are provided in positions respectively underlying and overlying the solder bump (15) for the signal. The openings may be sized to provide a desired ratio of inductance to capacitance, the larger the size, the greater the ratio value. This technique may be used to match characteristic impedance to give broad bandwidth low impedance interconnections needed for direct SFQ chip-to-chip communication on a passive MCM.

Abstract: A superconductor on-chip microstrip line (2, 4) to off-chip microstrip line (7) transition of low characteristic impedance (15, 20, 22) is realized that obtains a bandwidth of 200 GHz for MCM application while employing solder bump (15, 17) technology to connect the chips (3, 5) to the off-chip microstrip and substrate (6). Circular openings (20, 22) through the respective ground plane layers (10 & 16) of the off-chip and on-chip microstrips are provided in positions respectively underlying and overlying the solder bump (15) for the signal. The openings may be sized to provide a desired ratio of inductance to capacitance, the larger the size, the greater the ratio value. This technique may be used to match characteristic impedance to give broad bandwidth low impedance interconnections needed for direct SFQ chip-to-chip communication on a passive MCM.

Abstract: Operating high frequency cryogenic superconductor devices requires an enclosure that permits application of wide band RF signals from an external source to the superconductor device while maintaining the device at cryogenic temperatures in an essentially magnetic field free environment. A magnetic field shielding enclosure is formed of inner (5, 7) and outer (9, 11) mumetal containers, one larger than the other in size. Each of those containers is formed of two open-ended container like pieces that are nested together with overlapping side walls to define two generally closed regions, the first containing the cryogenic superconductor device (1) and the second (9, 11) containing the first container (5, 7). A shielded high bandwidth transmission line (12), sufficiently compliant physically, is snaked through slight clearance spaces between the pieces of each of those containers to the superconductor device.