The device they're describing is already known in microwave engineering, it's not a new circuit. It's a parametric-modulated circulator - the capacitance is mod

The device they're describing is already known in microwave engineering, it's not a new circuit. It's a parametric-modulated circulator - the capacitance is modulated. Not very useful in real-life: the PR-heavy letter neglects to mention (1) the poor instantaneous bandwidth <0.5% (figure 4c), (2) the poor linearity / poor power handling: Vm and Vdc are few volts in high-Q environment, which translates into maximum power handling well below 0dBm (3) the high sensitivity to analog component variation (fig 4c again) - not something you want in mass-produced components operating at commercial/industrial temperature ranges. They neglected to mention the power level they used to measure the S-parameters in the letter or the supplementary material. No self-respecting RF engineer would forget to mention power levels - it again hints at very poor linearity / poor power handling. Typical university "research".