Photonic-assisted reconfigurable ultra-wideband fast frequency-hopping signal generation

A photonic-assisted reconfigurable ultra-wideband frequency-hopping (FH) signal generation scheme is proposed to generate microwave FH signals with wide frequency coverage, fine frequency resolution and fast reconfigurability. In this scheme, direct digital synthesis (DDS) is employed to achieve kHz-level fine frequency tuning, while wavelength division multiplexer (WDM) and semiconductor optical amplifier (SOA) are used for coarse comb-line selection. By exploiting the Vernier effect between dual optical frequency combs (OFCs), reconfigurable FH signals covering 2–40 GHz are experimentally generated with a hopping rate of 2 × 10 5 hops/s and a frequency step of 1 kHz. The communication capability of the generated FH carrier is further evaluated using a 2-GHz-bandwidth QPSK signal, where the measured EVM remains within 15%–19% over the 4–40 GHz frequency range. The proposed scheme offers a flexible photonic approach for generating reconfigurable ultra-wideband FH microwave signals, showing potential for secure wireless communication, spectrum-agile radio systems, and wideband radar systems.