  We study nonreciprocal microwave transmission based on the
Gebhard-Ruckenstein hopping. We consider a superconducting device that consists
of microwave resonators and a coupler. The Gebhard-Ruckenstein hopping between
the resonators gives rise to a linear energy dispersion which manifests chiral
propagation of microwaves in the device. This device functions as an on-chip
circulator with a wide bandwidth when transmission lines are attached.
