Title :
A Two-Dimensional Optical True Time-Delay Beamformer Consisting of a Fiber Bragg Grating Prism and Switch-Based Fiber-Optic Delay Lines
Author :
Jung, Byung-Min ; Yao, Jianping
Author_Institution :
Sch. of Inf. Technol. & Eng., Univ. of Ottawa, Ottawa, ON
fDate :
5/15/2009 12:00:00 AM
Abstract :
A two-dimensional optical true time-delay (TTD) beamforming system for a planar phased array antenna (PAA) is proposed and demonstrated. The optical beamforming system consists of a fiber-Bragg-grating-prism-based wavelength-dependent TTD (WD-TTD) unit for azimuth beam steering and a microelectromechanical-system-switch-based wavelength-independent TTD (WI-TTD) unit for elevation beam steering. The time delays generated by the WD-TTD and WI-TTD are measured. The results show that the proposed system can achieve the required time delays with the time-delay errors for the WD-TTD and the WI-TTD at 1 GHz less than 11.8 and 3.6 ps, which correspond to radiation direction errors of less than 1.5deg and 0.4deg for a planar PAA with the adjacent array elements spaced by a half radio-frequency wavelength.
Keywords :
Bragg gratings; beam steering; micro-optomechanical devices; microswitches; optical arrays; optical communication equipment; optical delay lines; optical fibre communication; optical prisms; optical switches; planar antenna arrays; wavelength division multiplexing; WD-TTD measurement; WI-TTD measurement; azimuth beam steering; fiber Bragg grating prism; frequency 1 GHz; half radio-frequency wavelength; microelectromechanical system; planar phased array antenna; switch-based fiber-optic delay line; time-delay error; two-dimensional optical true time-delay beamformer; wavelength-dependent true-time delay; wavelength-independent true time-delay; Fiber Bragg grating (FBG); optical fiber delay lines; phased array antennas (PAAs); true time-delay (TTD);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2009.2015275
