No abstract

Spectrum analysis is a key functionality in modern radio frequency (RF) systems. In particular, fast and accurate estimation of multiple unknown RF signal frequencies over a wide measurement range is crucial in defense applications. Although photonic techniques benefit from an enhanced frequency estimation range along with reduced size and weight relative to their RF counterparts, they have been limited by a fundamental trade-off between measurement range and accuracy. Here, we circumvent this trade-off by harnessing the photon and phonon interactions in a photonic chip through stimulated Brillouin scattering, resulting in an accurate estimation of multiple RFs of up to 38 GHz with a record-low error of 1 MHz.

No abstract

A photonic scheme to generate a phase-coded microwave signal with tunable carrier frequency based on a simple single-trip and two-pass structure is proposed. Facilitated by the fiber Bragg grating and phase modulator along the trip, both frequency doubling and signal phase coding could be achieved simultaneously. Phase-coded microwave signals at 20 and 22 GHz are experimentally generated.