Enhanced Deep Subwavelength Direction-of-Arrival Sensing Using Time Modulation

We develop and analyze a model for a deep-subwavelength direction-of-arrival (DoA) sensor with enhanced performance and sensitivity, by incorporating time-modulation into the sensing system. We formulate the problem, derive an analytical model and equivalent circuit models, discuss the physical mechanisms responsible for the enhancement. We show that time-modulation enables a new degree of control over the operation frequency, and that incorporating the currents from higher generated harmonics into the sensing scheme allows us to extract more accurate information about the impinging wave.