Photonic-assisted radio frequency spectrum scanning device including: • a first optical waveguide arm; • a second optical waveguide arm; • a tunable single-wavelength laser, that is - connected to input ends of the first and second optical waveguide arms (210,220), and - operable to supply said first and second optical waveguide arms (210,220) with a single-wavelength optical signal having a single, tunable wavelength; • an optical hybrid coupler, that is - connected to output ends of the first and second optical waveguide arms (210,220), and - designed to combine optical signals received from said first and second optical waveguide arms (210,220) so as to produce corresponding optical in-phase and quadrature components; and • photodetection means (231,232), that are - connected to the optical hybrid coupler to receive the optical in-phase and quadrature components, and - configured to convert said optical in-phase and quadrature components into corresponding baseband electrical analog in-phase and quadrature components; wherein the first optical waveguide arm comprises an electro-optical modulator, that is designed to: • receive an incoming radio frequency signal; and • modulate the single-wavelength optical signal by means of the incoming radio frequency signal, thereby producing a modulated optical signal; and wherein the second optical waveguide arm comprises: • a coherent optical comb generator, that is designed to generate an optical wavelength comb on the basis of the single-wavelength optical signal; and • a fixed optical bandpass filter, that is designed to filter the optical wavelength comb so as to select a portion thereof, thereby producing a filtered optical signal. • a first optical waveguide arm; • a second optical waveguide arm; • a tunable single-wavelength laser, that is - connected to input ends of the first and second optical waveguide arms (210,220), and - operable to supply said first and second optical waveguide arms (210,220) with a single-wavelength optical signal having a single, tunable wavelength; - connected to input ends of the first and second optical waveguide arms (210,220), and - operable to supply said first and second optical waveguide arms (210,220) with a single-wavelength optical signal having a single, tunable wavelength; • an optical hybrid coupler, that is - connected to output ends of the first and second optical waveguide arms (210,220), and - designed to combine optical signals received from said first and second optical waveguide arms (210,220) so as to produce corresponding optical in-phase and quadrature components; and - connected to output ends of the first and second optical waveguide arms (210,220), and - designed to combine optical signals received from said first and second optical waveguide arms (210,220) so as to produce corresponding optical in-phase and quadrature components; and • photodetection means (231,232), that are - connected to the optical hybrid coupler to receive the optical in-phase and quadrature components, and - configured to convert said optical in-phase and quadrature components into corresponding baseband electrical analog in-phase and quadrature components; - connected to the optical hybrid coupler to receive the optical in-phase and quadrature components, and - configured to convert said optical in-phase and quadrature components into corresponding baseband electrical analog in-phase and quadrature components; • receive an incoming radio frequency signal; and • modulate the single-wavelength optical signal by means of the incoming radio frequency signal, thereby producing a modulated optical signal; • a coherent optical comb generator, that is designed to generate an optical wavelength comb on the basis of the single-wavelength optical signal; and • a fixed optical bandpass filter, that is designed to filter the optical wavelength comb so as to select a portion thereof, thereby producing a filtered optical signal.