Photonic Crystal Fiber-Based True-Time-Delay Beamformer for Multiple RF Beam Transmission and Reception of an X-Band Phased-Array Antenna

We report multiple beam transmission and reception of an X-band phased antenna array utilizing highly dispersive photonic crystal fiber (PCF), which has a dispersion value of - 600 ps/nm/km at 1550 nm, as true-time-delay (TTD) elements. In the transmission mode, two RF signals with frequencies 8.4 and 12 GHz are simultaneously steered at angles 7.4 and 21.2 degrees, respectively. In the receiving mode experiment, two RF signals with frequencies 8.4 and 12 GHz impinging upon an X-band antenna array from angles -7.4 and -21.2 degrees, respectively, are detected and the angles of arrival are determined accurately. Many RF beams can be simultaneously transmitted or received. The demonstration is only limited by the hardware availability and the bandwidth of the wavelength differentiation capability of the system.