  Integrated Kerr microcombs are emerging as a powerful tool as sources of
multiple wavelength channels for photonic RF and microwave signal processing
mainly in the context of transversal filters. They offer a compact device
footprint, very high versatility, large numbers of wavelengths, and wide
Nyquist bands. Here, we review recent progress on Kerr microcomb-based photonic
RF and microwave reconfigurable filters, based both on transversal filter
methods and on RF to optical bandwidth scaling. We compare and contrast results
achieved with wide comb spacing combs (200GHz) with more finely spaced (49GHz)
microcombs. The strong potential of optical micro-combs for RF photonics
applications in terms of functions and integrability is also discussed.
