A NEW DRIVE CIRCUIT BUILT IN A MULTICHIP-MODULE FOR SUPPLYING A 2-PHASE POWER TO JOSEPHSON LSI CIRCUITS

A new built-in drive circuit for superconducting Josephson LSI circuits has been designed and fabricated in a ceramic multichip module. The drive circuit consists of an impedance matching circuit and a DC bias current feeding circuit to supply a two-phase power current to Josephson chips at a microwave frequency. The impedance matching circuit was designed based on a quarter wavelength stripline. A balanced stripline configuration was introduced to reduce the fluctuation of ground potential. Tungsten layers were used to make the drive circuit in a multilayer ceramic substrate of the multichip module. Whole circuit was successfully packed in a volume of 76 mm x 38 mm x 1.7 mm. The gain of microwave current were 20 dB around 1.2 GHz and 23 dB around 3.6 GHz, which were in good agreement with the simulated current gain.