STEPPED IMPEDANCE RESONATOR BANDPASS FILTERS USING TAPPED-LINE FOR CONTROLLING SPURIOUS RESPONSE

摘要

A stepped impedance resonator bandpass filter was designed and implemented, combining with the tapped-line structure. The measured bandpass filters at the center frequency of 2.0 GHz has the characteristics: the insertion loss S{sub}21=-2.98 dB, BWR is 15.1%, and the transmission zeros occurred at 2.62 GHz with -48.5 dB. Especially, the wider rejection of -20 dB can be obtained form 2.4 to 8.2 GHz from the proper position of tapped-line I/O. The designed filter shows the excellent abilities to shift and suppress the spurious response by properly designing the structure of the resonator. The proposed filter was designed and fabricated, and the performances closely matched the simulation results.