Superconducting quantum devices

Abstract:

A novel compact implementation is introduced, providing contiguous multiplexing of channels with extreme bandwidth differences. It relies on the combination of the direct branching approach with the ‘all-resonator’ multiplexing method. It accommodates the implementation of nearly arbitrary filter functions for different channels, incorporating transmission zeros (TZs) to meet the rejection demands between contiguous channels with a reasonable filter order. The proposed approach has been applied to a contiguous Ka-band multiplexer design with 15.5% overall bandwidth, serving four channels with three different channel bandwidths: 11.7%, 2.1%, and two channels of 0.6% each. Accordingly, different filter functions are applied - namely, 12th-, 8th-, and 6th-order filters - each providing two TZs. The wideband channel is separated at the common branching from the other three channels, which are served by an adapted all-resonator multiplexing method. The final multiplexer design proves high RF performance with a very compact implementation.