Narrow-band microwave filter design

Abstract

In this article, Dishal's concepts, EM simulation, and the port-tuning concept are combined as a powerful procedure for narrow-band filter design. When applied to an EM-based filter prototype, port tuning gives a direct indication of the magnitude and direction of the tunings needed to correct coupling errors and resonator frequency errors. An EM-based filter prototype potentially captures all the physics of the real hardware and includes second-order effects that may be impossible to describe using analytical models. After iteratively reducing all the errors in the EM-based prototype, the first hardware prototype that was built will meet performance goals. This design methodology can be applied to simple all-pole Chebyshev filters and to more complex cross-coupled filters that place transmission zeros in the stopbands.