Air-filled Substrate-Integrated Waveguide Technology for Broadband and Highly-Efficient Photonic-Enabled Antenna Systems

The combination of microwave photonics, radio-over-fiber (RoF) and air-filled substrate-integrated-waveguide (AFSIW) technology opens many promising pathways to realize robust, broadband, and highly-integrated multi-antenna systems that address the stringent demands of (beyond-)5G wireless applications. In this paper, we demonstrate the potential of such a multi-disciplinary approach by discussing three designs. First, two AFSIW-based photonic-enabled remote antenna units (RAUs) are presented for downlink sub-6GHz RoF. By adopting an extensive full-wave/circuit co-simulation model, the power transfer between the optical and electrical domain is maximized. In the first design, this is done by using a Chebyshev impedance matching network, while the second design exploits conjugate matching. Second, a hybrid integration strategy for compact, broadband and highly efficient mmWave antennas is introduced. Its excellent performance is proven by realizing an on-chip AFSIW stacked patch antenna. In addition, the design facilitates compact integration of the opto-electronic front-end, making it attractive for the realization of next-generation photonic-enabled mmWave planar multi-antenna systems.