Homotopy-Based Synthesis for Microwave Filter with Acoustic Wave Resonators: Preserving Key Features using Pseudo-BVD Elements

This paper presents a comprehensive mathematical model for acoustic wave (AW) resonator filter design using microwave filter synthesis theory. A straightforward circuit synthesis method is introduced to derive a ladder network with pseudo-BVD (PBVD) elements, eliminating the need for coupling elements as intermediates. The homotopy continuation (HC) method is employed to determine the exact transition process from PBVD to standard BVD model, ensuring both stability and accuracy while preserving overall network performance. This approach bridges the gap between idealized microwave filter design and AW filter network synthesis, providing an efficient solution to complex filter design challenges. It effectively addresses the design objectives while maintaining critical network features.