Title :
Broadband microwave fiber-optic links with RF phase control for phased-array antennas
Author :
Georges, John B. ; Lau, Kam Y.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., California Univ., Berkeley, CA, USA
Abstract :
The authors report the use of injection-locked self-pulsing laser diodes as optical transmitters in RF fiber-optic links, in which the RF phase of the transmitted signal can be continuously adjusted by simply varying the bias current into the laser. These devices are intended for use in optically-controlled phased-array antenna systems or in optical networks for the remote synchronization of antenna stations. It is demonstrated that by using a commercial, low-cost, compact-disk self-pulsing laser diode, phase shifting over a range of 180 degrees is possible over a broad operational frequency band of 1-7 GHz, with a switching time of <5 ns and a phase resolution of <1 degrees . This phase shifter/optical link can also exhibit inherent electrical gain of up to 10 dB and an RF isolation of >80 dB with proper impedance matching of the laser and photodetector.<>
Keywords :
antenna phased arrays; microwave antenna arrays; microwave links; optical communication equipment; optical links; phase control; semiconductor lasers; transmitters; 1 to 7 GHz; 10 dB; 5 ns; RF fiber-optic links; RF isolation; RF phase control; SHF; UHF; antenna stations; bias current; broadband antennas; electrical gain; impedance matching; injection-locked self-pulsing laser diodes; optical networks; optical transmitters; phase resolution; phase shifting; phased-array antennas; photodetector; remote synchronization; switching time; Diode lasers; Fiber lasers; Masers; Microwave devices; Optical fiber devices; Optical fiber networks; Optical transmitters; Phase control; RF signals; Radio frequency;
Journal_Title :
Photonics Technology Letters, IEEE