  We report a dual-polarization radio frequency (RF) channelizer based on
microcombs. With the tailored mismatch between the FSRs of the active and
passive MRRs, wideband RF spectra can be channelized into multiple segments
featuring digital compatible bandwidths via the Vernier effect. Due to the use
of dual polarization states, the number of channelized spectral segments, and
thus the RF instantaneous bandwidth (with a certain spectral resolution), can
be doubled. In our experiments, we used 20 microcomb lines with 49 GHz FSR to
achieve 20 channels for each polarization, with high RF spectra slicing
resolutions at 144 MHz (TE) and 163 MHz (TM), respectively; achieving an
instantaneous RF operation bandwidth of 3.1 GHz (TE) and 2.2 GHz (TM). Our
approach paves the path towards monolithically integrated photonic RF receivers
(the key components active and passive MRRs are all fabricated on the same
platform) with reduced complexity, size, and unprecedented performance, which
is important for wide RF applications with digital compatible signal detection.
