Wideband array transmitter with two-dimensional fiber-optic beam steering

We demonstrate a wideband transmit array with two-dimensional fiber-optic true time-delay steering. The separate azimuth and elevation steering control stages are based on a simple dispersive fiber-optic prism approach. The prism´s individual fiber feeds include an amount of dispersion proportional to the relative position of the radiating element in the array. The microwave signals are transmitted on wavelength tunable optical carriers and are properly time-delayed by setting the azimuth and the elevation control wavelengths. The array is comprised of flared-notch elements arranged in a 4×4 configuration, and the transmitter shows a microwave component-limited bandwidth of 6-18 GHz. The anechoic chamber two-dimensional array pattern measurements show frequency-squint-free independent beam steering over ±40° in azimuth and ±40° in elevation