10-Gb/s/ch QPSK FDM W-band radio-over-fiber signal generation, free-space radio transmission, and its demodulation

10-Gb/s/ch frequency-division-multiplexing (FDM) radio-over-fiber (RoF) signal generation and free-space transmission in W-band (75-110 GHz) are successfully demonstrated. The FDM quadrature-phaseshift-keying (QPSK) signals with 3 channels are optically generated and transmitted over 30-cm radio link. Digital signal processing with W-band mixer realizes successful demodulation of its FDM radio signal.