Demonstration of a continuously variable true-time delay beamformer using a multichannel chirped fiber grating

A continuously variable true-time delay beamformer based on a multichannel chirped fiber grating (MCFG) is demonstrated. The beamformer is capable of wide-band squint-free operation and demonstrates beam steering of a four-element array over ±40°. The use of an MCFG provides a significant reduction in the length of the chirped grating required, eliminates spurious signal transmission, and utilizes narrow-band tunable laser sources. In addition, the effect of grating errors on the antenna pattern is examined and the tolerance on performance is presented.