A New Class of Ultra-Wideband Beamforming Networks for sub-6 GHz Bands

In this work, a novel beamforming scheme is introduced that covers the sub-6 GHz bands for both satellite and terrestrial communication systems. To achieve multi-octave performance, we adopt the concept of microwave photonics and we appropriately implement it in the microwave-millimeter waves (mmWaves) regime. Specifically, in our proposed network, the desired sub-6 GHz signals are first upconverted to a mmWave frequency band where the beamforming signal processing takes place. The resulting signals are then downconverted to their original frequency band before being fed to their corresponding antenna ports for transmission. To validate our concept, a novel analog beamformer is designed, fabricated and measured, and a virtual test-bed is designed and simulated. Based on our measured and simulated results we show that our beamforming network can support bandwidths up to 6 : 1, which to our knowledge are the highest reported in the literature.