Course 2: Introductory Course on Microwave filters

To introduce the concepts behind microwave filters highlighting the potential and limitations of these devices in the practical applications

Lesson 1:

Introduction – Definition of filters‐ Specifications: Filter Mask ‐ Design approaches for distributed parameter filters – General recipe for microwave filters design. Software aids. Recall of microwave circuit fundamentals for filter design: equivalent circuit concept, resonators, resonant modes, coupled resonators, examples, and discussion. Fabrication technologies and their impact on filter feasibility

Lesson 2:

Basics of lumped filters synthesis: equivalent low‐pass domain, frequency transformation, impedance conservation property. Analytical solutions for all‐pole functions (Butterworth, Chebycheff). Equations for the elements of ladder low‐pass prototype. De‐normalized band‐pass network is suitable for microwave implementations. Universal parameters characterizing the de‐normalized filter model (coupling coefficients and resonating frequencies). Examples of all‐pole in‐line microwave filters (waveguide, microstrip, and coaxial implementation).

Lesson 3:

Why introduce transmission zeros in the filter response? Approximating characteristics including transmission zeros (Generalized Chebycheff). Topological solutions (cross‐coupled and extracted‐pole topologies). The normalized coupling matrix. Practical examples (coaxial & waveguide) and discussion.

Lesson 4:

Introduction to microwave filters dimensioning (with the aid of circuit and EM simulators)