Basic Characteristics of a Quarter-Wavelength CPW Resonator with Tap-Feed Structure and Its Application to a Bandpass Filter with Attenuation Poles

摘要

Properties of a quarter-wavelength coplanar waveguide resonator such as resonant frequency, external quality factor (Q_e) are characterized by a theoretical approach and verified by the experiment. The unloaded quality factor (Q_o) of the resonator is also examined experimentally. After new types of combline bandpass filter (BPF) made of these resonators are realized, their transmission and reflection characteristics are examined theoretically and experimentally. A new combline BPF having attenuation poles are also realized.