  We propose and demonstrate reconfigurable fractional microwave signal
processing based on an integrated Kerr optical microcomb. We achieve two forms
of microwave signal processing functions, a fractional Hilbert transform as
well as a fractional differentiator. For the Hilbert transform we demonstrate a
phase shift of 45 degrees, half that of a full Hilbert transform, while for the
differentiator we achieve square-root differentiation. For both, we achieve
high resolution over a broad bandwidth of 17 GHz with a phase deviation of less
than 5 per degree within the achieved passband. This performance in both the
frequency and time domains demonstrates the versatility and power of
micro-combs as a basis for high performance microwave signal processing.
