Dr. Songbin Gong and his group from the University of Illinois have developed a framework for synthesizing frequency-independent multi-port nonreciprocal networks. The framework is highly expandable, can have an arbitrary number of ports while simultaneously sustaining balanced performance, and provide unprecedented programmability of non-reciprocity. Unlike the conventional approaches, non-reciprocal performance of the network is only dependent of the time delays, instead of phase delays, and therefore is frequency independent. This technology could inspire new ways of implementing multiple input multiple output (MIMO) communication systems.
4-port switch module prototype