With their increased data capacities, 4G and 5G wireless communications networks require impressive backhaul links. These networks must not only send large amounts of data between a mobile user and a base transceiver station, but also between different nodes in the network and eventually to the main switching station for entry into the internet backbone. Wireless backhaul connections are typically made by fiber-optic cables or by microwave radios.
With the increased data capacities of 4G and 5G networks, these microwave radio links must take advantage of the wider bandwidths at higher operating frequencies, typically including 24 GHz, 38 GHz, 42 GHz (in Europe), and at unlicensed bands of 60 GHz and higher. Generating and processing these millimeter-wave frequencies are not trivial tasks. The loss budgets for microwave radios operating at these higher frequencies become critical, for example, when available power typically diminishes with increasing frequency.
When designing components for these higher frequency microwave radios and wireless backhaul equipment, designers must understand the losses affecting a radio’s signal strength from a materials perspective, in particular dielectric losses and conductor losses. Materials nominally developed for use at frequencies below 40 GHz must be modified for suitable performance at higher frequencies. E-band microwave radios require ultra-low-loss dielectrics based on PTFE or advanced thermoset technologies.
Rogers has optimized its portfolio of ultra-low-loss circuit materials for higher frequency use by minimizing conductor losses through the use of reduced-roughness copper. Microwave radios from 6 to 80 GHz today use Rogers' low loss materials and low profile copper foils to provide a complete range of backhaul solutions.