Out of Band Improved Performance Into a Measured 5G N77 Band Transversal Filter

Transversal networks for electroacoustic filters had been proposed and manufactured recently [1]. One of the main problems that arose in the first prototype were the spurious modes due to the mirror stack of the Solidly Mounted Resonators (SMR). In this work, different approaches for solving this problem are discussed, relying on Mason's circuit-based simulations of each resonator and of the filter topology. The main drawbacks and advantages of the different approaches are discussed in terms of fabrication and mirror efficiency.