Broadband millimeter-wave optical transmitters for fiber-wireless communications links.

摘要

Bringing the information superhighway to the home requires broadband, two-way and high-capacity communications links. A wireless system is a quick and cost-effective method of delivering broadband services to a large density of fixed and mobile users. To provide broadband wireless services to a large number of users in a fixed service area, a microcellular architecture with many base stations transmitting and receiving signals to and from users is needed. Due to frequency crowding at the lower frequency free-space communications bands, only the millimeter-wave (mm-wave) frequency band (;Optical fiber links provide a low loss, high bandwidth connection from a central office to the remote base station antennas. In addition, there are important advantages to sending the mm-wave information directly over the optical fiber, such as simplification of base station electronics, centralized control of the mm-wave signals, and stabilization of the mm-wave signals. This dissertation provides analyses showing the importance of broadband mm-wave fiber optic links for distribution to mm-wave antennas.;Although commercially available optical fiber and optical receivers have mm-wave bandwidths, mm-wave optical transmitters are not readily available. The main portion of this work is devoted to methods of broadband mm-wave optical transmission. The feedforward optical modulator, the feedback optical modulator, and the electro-optic upconverter produce broadband mm-wave optical modulation through new and non-conventional means. Complete theoretical and experimental analyses of these transmitters are presented.;Finally, the transmission of broadband mm-wave optical signals over long optical fiber distances for distribution links can be significantly affected by fiber chromatic dispersion. This problem is studied in depth both theoretically and experimentally, and a simple solution using single-sideband optical modulation is presented.