SAW Filters Substrates for 5G Filters

Taking into account the changes caused by the introduction of the new 5G mobile communications standard, the requirements for SAW filters are formulated and their relationship with the parameters of the filter substrates is shown. Based on the analysis of current publications of the last three years, the author identified and confirmed by examples the main trends in current research and development of SAW filter substrates for 5G filters. It is shown that the requirements of 5G force, and the achievements of modern technologies of direct material bonding allow to change the entire approach to the manufacture of substrates. It is demonstrated that only multilayer substrates made of composite materials and innovative technologies for mass industrial production of substrates specifically oriented to 5G requirements, such as POI technology, can meet current requirements. The problems that exist in the fabrication of multilayer film substrates and possible ways to increase the operating frequencies and improve the performance of filters are discussed