Design of single narrow band bandpass filter using cascaded open loop triangular ring resonators embedded with rectangular ring

This paper presents a compact single narrow band bandpass filter using two cascaded open loop triangular ring resonator embedded with rectangular ring for various application at 11.8 ghz in microwave communication systems. coupled resonator theory was used for coupling parasitic resonance of multiple degenerate modes operating close to the fundamental mode in the proposed structure of filter. the frequency response has low insertion loss and good rejection performance of the proposed filter. the filter was easy to fabricate since there was no use of via or defected ground structure. cascading and the embedded rectangular ring were used to improve the stop band performances by creating several attenuation poles. a wide stop band was obtained at both the sides of passband. the proposed filter was designed and simulated in agilent advance design system. the simulated result and the measured results were in good agreement.