Analytical Synthesis of Acoustic Wave Duplexers and Multiplexers

This work demonstrates the exact synthesis of acoustic wave (AW) multiplexers for the first time, building on pioneering works in coaxial cavity multiplexers. The presented approach computes the multiport polynomials composing the multiplexer and derives a set of distorted characteristic polynomials for each AW ladder filter so that they form a practically equiripple response when connected to a star junction. Each channel can then be synthesized independently to obtain the Butterworth - Van Dyke model of its resonators. This approach avoids intensive optimization procedures and represents a useful technique for the design of carrier aggregation filter modules in a direct manner.