An on-Chip Planar Broadband 3-Way Power Divider for Josephson Voltage Circuits

This article presents a superconducting material based planar broadband 3-way Wilkinson power divider which can be used in the Josephson quantum voltage device for the voltage standards. The 3-way Wilkinson power divider aims to improve the integration of Josephson voltage device compared to the commonly used 2-way power divider. A two-stage λ/4 section on each branch is used to increase the bandwidth, and a π model with lumped equivalent elements are used to further decrease physical dimension in device area. Different from the conventional spatial design of N-way Wilkinson power divider, this work designs a planar broadband 3-way divider to be compatible with the on-chip fabrication process. Simulation results show that the insert loss is below 0.18 dB at working bandwidth of 16.7~23 GHz, the division imbalance of each branch is below 0.044 dB, and the input and output reflection is better than 15 and 11.9 dB, respectively. The isolation between any of the three output ports is better than 11.8 dB. All these indexes satisfy the requirement of the Josephson voltage standard application. To further prove the validity of our design, real device based on superconducting material is realized and characterized. Devices with a 3-way power divider and three 2-stacked Josephson junction arrays with 256 junctions in each array are fabricated. The experiment results indicate the potential usage of our design in quantum voltage standard devices for high-voltage output.