COMPACT SEMILUMPED BANDSTOP RESONATORS USING THE CAPACITIVELY LOADED PARALLEL-COUPLED MICROSTRIP LINE

摘要

Compact semilumped bandstop resonators are simply designed using parallel-coupled microstrip line and lumped capacitors. The lumped capacitors loaded in between coupled lines increase the odd mode electrical length, and the frequency of transmission zero can be controlled by the lumped capacitors. For the accurate estimation of the transmission zero frequency, the four-port impedance parameter is derived using the even/odd mode analysis in an inhomogeneous dielectric medium. Two types of the bandstop resonators are proposed using the coupled line with the length of λ{sub}g/8(@2 GHz), and the calculated and measured results of transmission zero frequency are compared in 1-3 GHz ranges.