Improved Photonic True Time Delay Unit for a Ku-Band Phased Array Antenna Demonstration

ABSTRACT

In this letter, a Photonic True Time Delay (PTTD) unit for phased array antennas is experimentally demonstrated. The PTTD unit, employing a single wavelength laser source, exploits the distributed photonic bandgap offered by a Linearly Chirped Fiber Bragg Grating (LCFBG) to attain different time delays by properly actuating the physical and geometrical features of the LCFBG through temperature changes. The time delay response of the TTD unit has been measured experimentally revealing multiband operation capability (S, C, X and Ku bands) with ps time delay resolution and a maximum dynamic range of 250ps. The time steering demonstration has been performed by characterizing in the Ku band an array prototype within a Near Field range.