Monolithically integrated photonic beamforming for a phased array receiver antenna

This is the authors' abstract. We don't add key points for this paper.

We present, to the best of our knowledge, the first monolithically integrated RF-in/IF-out photonic beamformer for a phased-array receiver antenna, fabricated on an \(8× 4~mm^2\) Indium Phosphide die. The beamformer is designed to receive four input RF signals and one RF local oscillator, convert them to the optical domain, apply complex weighting, and down-convert the added signals to a beamformed IF output. The presented photonic beamformer is enabled by a novel laser generation stage requiring no isolation, injection locking, or optical filtering. A conversion loss of 79 dB was measured, primarily dominated by lossy passive devices. Despite the significant conversion loss, beamforming was demonstrated for three beam orientations, \(0^∘\) and \(± 30^∘\) , for \(fRF=10\) GHz, \(fLO=14\) GHz and \(fIF=4\) GHz, using three out of four designed channels, and considering a virtual linear phased array antenna receiver.