Limitations by Group Delay Ripple on Optical Beam-forming With Chirped Fiber Grating

This paper investigates the effect of group delay ripple on optical beam-formers using chirped fiber grating. Such optical beam-formers were promised to have many advantages over their electrical beam-forming counter-parts. However, mathematical analysis and simulation results have shown that the group delay ripple causes many drawbacks such as the limitation in operation frequency, RF signal bandwidth, and the number of elements. The most advantageous feature of optical beam-formers, which is squint-free operation for wideband, high frequency signals, is severely affected when chirped grating is used.