Optical millimeter-wave systems for broadband mobile communications, devices and techniques

Future mobile communication systems have to meet the demands of broadband services. The 60 GHz-range is proposed for the radio link frequency in these cellular systems. The combination of optical techniques and millimeter-wave techniques at these frequencies is a promising approach for cost-effective network implementation. Besides the low-loss fiber-based data transmission, this combination allows simple millimeter-wave generation in low-cost base stations. In this paper different techniques of optical millimeter-wave generation are briefly reviewed and some experiments on the optical generation of low-phase noise millimeter-wave signals and offset quadrature phase shift keying (OQPSK) 140 Mbit/s-data transmission are reported. Quartz stable millimeter-waves at 18-20 GHz and in the 60 GHz band are remotely generated by heterodyning the signals of semiconductor lasers.