Recent advances in spatiotemporally-modulated (STM) magnetless circulators

We present our recent advances on the design of spatiotemporally modulated (STM) magnetless circulators based on angular-momentum biasing. We show the two main topologies that can be used to design such devices, in particular wye with series LC resonators and delta with parallel LC resonators, and discuss their respective advantages. We show how we can reduce insertion loss by cancelling the additional harmonics resulting from modulation through the use of a differential topology. We also show how we can extend the bandwidth by adding passive matching circuits at the ports of the circulator. Finally, we discuss the implementation of such devices in an integrated circuit.