Basic Structure and Characteristics of SIR

Abstract

Transmission-line resonators are most frequently used in frequency regions above the VHF band, yet, as described in the previous chapter, most applications employ structures with uniform characteristic impedance. Transmission-line resonators possessing a stepped-impedance structure (SIR) have long been known as an available resonator structure, and are often used to experimentally examine the effect of discontinuity in the impedance step of a transmission line [1]. However, this stepped impedance structure was hardly ever used for practical circuits, with the exception of impedance transformers.