Measurement of crosstalk between crossing superconductor microstrip lines

We experimentally evaluated the effect of crosstalk between crossing microstrip lines (MSLs) on our MSL receiver. The measurement circuit consisted of two crossing MSLs, referred to as the upper MSL and lower MSL. At the crossing area, the upper MSL and lower MSL were separated by a 400-nm thickness Of SiO2 thin film. The parasitic capacitance between them was estimated to be about 0.1 pF. We measured bias margin of the receiver connected to the lower MSL under two conditions: with a pulse train running through the upper MSL, i.e., with crosstalk noise, and without a pulse train in the upper MSL, i.e., without crosstalk noise. Our measurements showed that (i) crosstalk mainly reduced the lower limit of the receiver's bias margin, and (ii) this reduction of bias margin was enhanced by resonance when the repetition frequency of pulses in the upper ring satisfied resonance condition. (C) 2003 Elsevier B.V. All rights reserved.