Q-factor evaluation of traveling-wave ring resonator in Magnet-less Non-reciprocal Metamaterial (MNM)

MNM (Magnet-less Non-reciprocal Metmaterial) is a technology to realize gyrotropic magnetic response by the combination of uni-directional component and resonant particle. As same as natural magnetic material, performance can be evaluated by half value of resonance width, which is inverse to Q-factor from viewpoint of resonator. In this paper, Q-factor of a unit-cell of MNM is estimated by circuit model consisting of FET and resonator model. The result clearly indicate the Q-factor of MNM unit-cell clearly depends on external factors expressed by load, which can be attributed to electromagnetic coupling to another system.