Microwave Photonic Self-Adaptive Bandpass Filter and its Application to a Frequency Set-on Oscillator

Linear frequency networks are a class of analog systems comprising nonlinear elements but which have a linear relationship between the input and output instantaneous frequency. Examples of such networks find applications in self-adaptive bandpass filters and frequency set-on oscillators. Early implementations of these linear frequency networks were built exclusively with RF and microwave components, resulting in limited bandwidths. Here, we demonstrate their implementation with microwave photonics, which enables broader bandwidth operation with lower propagation losses (and hence longer delay lengths) for the development of, for example, high-Q set-on oscillators.