Structure and Design of Compact Bandstop Filter

In order to suppress the spurious signals,the band-stop filter is required to be used in the communication system.The band-stop filter has been designed by adopting Chebyshev low-pass prototype,the series resonance circuits were realized by the dielectric coaxial resonator loaded with capacitor,a quarter wavelength transmission lines were realized by π-type networks.A band-stop filter with center frequency of 933 MHz and stop-band attenuation of more than 40 dB has been made using the microwave dielectric material with high Q and high dielectric constant.The measurement accorded with the design requirements.The filter was characterized by small size and high performance with stability.