Chirped fiber grating and specialty fiber based multiwavelength optical beamforming network for 1X8 phased array antenna in S-band

Abstract

In this paper, theoretical and experimental analysis has been done for the beam transmission of 2.2 GHz RF signal by 1X8 linear phased array antenna fabricated in S-band. The proposed architecture is based on true time delay optical beam forming network which gives squint free beam steering of RF signal. The optical beam forming network is based on chirp fiber Bragg grating (CFBG) and multiple lengths of highly dispersive specialty fiber element. Here, double sideband modulation technique of multiple wavelengths are adopted which explore the reflection property of CFBG with various chirp bandwidth. We measured the reflectivity and time delay response of CFBG, and dispersive fiber elements with theoretical analysis which is verified by experimental results. Theoretical and experimental measurements for the relative time delay was used to investigate the beam radiation pattern of 1X8 phased array antenna through simulation results. Wide range of beam steering ranges 3.5° to 18° have been achieved when specialty fiber of −100 ps/nm km dispersion coefficient was introduced.