by U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology in Gaithersburg, MD .
Written in English
|Other titles||2 D true time delay generation using fiber chirp gratings and acousto-optic beam deflectors|
|Statement||Eung Gi Paek, Joon Y. Choe, Tae K. Oh|
|Series||NISTIR -- 6038|
|Contributions||Choe, Joon Y, Oh, Tae K, National Institute of Standards and Technology (U.S.)|
|The Physical Object|
|Number of Pages||10|
A compact high frequency true time delay (TTD) beamformer using bidirectional reflectance of the fiber gratings (FGs) is proposed. The FGs can be a set of fiber Bragg gratings (FBGs) or chirped fiber gratings (CFGs). The number and the length of the time delay lines are greatly reduced compared to the previous by: Therefore, the TLCFG delay line is a true-time-delay beamformer and is suit- able for wideband applications. For our system, the time delay difference is determined by the chirp rate of the chirped grating and the wavelength spacing of the optical carriers. We have demonstrated a continuous phased-array antenna beam former based on a variable photonics true-timedelay unit consisting of four chirped gratings. The system is suitable for the phased-array antenna beam forming at frequencies up to 20 by: 7. The time delay requirements for a 4×4 subarray of a PAA with. ±45◦ steering angle across X, Ku, and K frequency bands. and a is the core radius, n1 and n2 are the refractive indices of the core and cladding, respectively, and is the free space propagating wavelength.
Optical true-time-delay (TTD) technique is an emerging technology that is capable of providing these features along with the ability to provide frequency independent beam steering. This type of fiber true time delay module can be implemented into an optically fed phased array antenna system similar to that described by Shi et al.. To the authors’ knowledge, this work is the first time that a thermally tuned bare optical fiber is demonstrated to generate time delay values for a phased array by: 5. We presented a method to actualize the optical vortex generation with wavelength tunability via an acoustically-induced fiber grating (AIFG) driven by a radio frequency source. The circular polarization fundamental mode could be converted to the first-order optical vortex through the AIFG, and its topological charges were verified by the spiral pattern of coaxial interference between the first Cited by: 2) of the optical material, electrode geometric factors (L/H) and inversely proportional to the square of the wavelength. ACOUSTO OPTIC MATERIAL SELECTION A variety of acousto-optical materials are used for Acousto Optic Modulators depending on the laser parameters such as wavelength, polarization, and power Size: KB.
A new 2-D true time delay (TTD) generation system architecture for phased array antennas is described. The method uses fiber chirp gratings and acousto-optic beam deflectors. By combining free-space optics and guided optics, the device complexity in conventional Cited by: 1. Xinyong DONG: Intensity-Modulated Optical Fiber Sensors Based on Chirped-Fiber Bragg Gratings measured), etc, but excluding transmission loss of the grating. ρ(λ) and R(λ) are the power spectral density of the broadband light source and the reflectivity of . A new 2-D true time delay (TTD) generation system architecture for phased array antennas is described. The method uses fiber chirp gratings and acousto-optic beam deflectors. By combining. Vol NISTIR 2-D true time delay generation using fiber Chirp gratings and acousto-optic beam deflectors by Paek, Eung Gi; Choe, Joon Y.; Oh, Tae K.