We report a broadband radio
frequency (RF) channelizer with up to 92 channels using a coherent microcomb
source. A soliton crystal microcomb, generated by a 49 GHz micro-ring resonator
(MRR), is used as a multi-wavelength source. Due to its ultra-low comb spacing,
up to 92 wavelengths are available in the C band, yielding a broad operation
bandwidth. Another high-Q MRR is employed as a passive optical periodic filter to
slice the RF spectrum with a high resolution of 121.4 MHz. We experimentally
achieve an instantaneous RF operation bandwidth of 8.08 GHz and verify RF
channelization up to 17.55 GHz via thermal tuning. Our approach is a significant
step towards the monolithically integrated photonic RF receivers with reduced
complexity, size, and unprecedented performance, which is important for wide RF
applications ranging from broadband analog signal processing to
digital-compatible signal detection.
Photonic RF channelizer based on 49GHz soliton crystal microcombs