Broadband lumped-element integrated n-way power dividers for programmable Josephson voltage standards
Mike Elsbury, Paul D. Dresselhaus, Norman F. Bergren, Charles J. Burroughs, Samuel P. Benz, Zoya Popovic
This paper presents a monolithically integrated broadband lumped-element Wilkinson power divider centered at 20 GHz, which was designed and fabricated to uniformly distribute power to arrays of Josephson junctions (JJs) for superconducting voltage standards. This solution achieves a fourfold decrease in chip area, and a twofold increase in bandwidth (BW)when compared to the previous narrowband distributed circuit. A single Wilkinson divider demonstrates 0.4-dB maximum insertion loss (IL), a 10-dB matchBWof 10 24.5 GHz, and a 10-dB isolation BW of 13 30 GHz. A 16-way four-level binary Wilkinson power divider network is characterized in a divider/attenuator/combiner back-to-back measurement configuration with a 10-dB match BW of 10-25 GHz. In the 15-22 GHz band of interest, the maximum IL for the 16-way divider network is 0.5 dB, with an average of 0.2 dB. The amplitude balance of the divider at 15, 19, and 22 GHz is measured to be 1.0 dB utilizing 16 arrays of 15 600 JJs as on-chip power detectors.
IEEE Transactions on Microwave Theory and Techniques