Rapidly Tunable Dual-Comb RF Photonic Filter for Ultrabroadband RF Spread Spectrum Applications

Abstract—a rapidly frequency-tunable radio frequency (RF) filter using microwave photonics technology for ultrawideband RF spread spectrum applications. A pair of electro-optic frequency combs is arranged as a dispersive tapped delay line in a differential detection configuration to implement a programmable finite impulse response RF filter. Our photonic scheme enables both fast frequency tuning on the order of tens of nanoseconds and wide tuning range (>7.5 GHz) with minimal variation of RF gain and passband shape. The low control voltage (ca. 1 V) and the linear relationship between control voltage and passband frequency facilitate agile frequency tuning for
processing of signals with time-varying frequency content, while differential detection increases the photocurrent by a factor of two and suppresses common mode intensity noise.< final year projects >