Broadband Lumped-Element Integrated $N$-Way Power Dividers for Voltage Standards

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> 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 match BW of 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 <formula formulatype="inline"><tex Notation="TeX">${\pm}{\hbox{1.0 dB}}$</tex></formula> utilizing 16 arrays of 15 600 JJs as on-chip power detectors. </para>