Broadband True Time Delay Microwave Photonic Beamformer for Phased Array Antennas

In this paper, we present results on true time delay-based, broadband, and continuously tunable photonic beamforming modules for phased array antennas. The RF beamforming module is based on hybrid optical integration of TriPleX and InP chips. We present two types of analog photonic links (APLs) to achieve true time delay (TTD) beamforming. The parameters of the individual integrated components and their impact on the APL are discussed together with the theory for the two APLs. The measurement results of two 1x4 TTD beamforming architectures are presented. The first is based on step wise delays with a bandwidth of 10 GHz and a link gain of about -46.4 dB. The second is based on continuously tunable delays with a bandwidth of 3.5 GHz and a link gain -39.8 dB.