Microchip design for a low-frequency Josephson-array voltage standard

The complexity of the Josephson array voltage standard can be reduced by using lower-frequency microwaves to excite the junction array. For operation at reduced frequencies, the design of the array must take the large size of the junctions, and the perturbing effect of the junction reactance on the distribution of microwave power into account. Such issues are especially important when durable, but low-capacitance, trilayer junctions are used in the array. These problems are minimized by a design in which the junction array is wound into a continuous spiral.