Title :
Quad-band bandpass filter based on dual-plane microstrip/DGS slot structure
Author_Institution :
Sch. of Electron. Eng., Univ. of Electron. Sci. & Technol. of China (UESTC), Chengdu, China
Abstract :
An approach for designing a quad-band bandpass filter is presented. The dual-plane structure composed of both a microstrip and a defected ground structure (DGS) slot is employed to obtain quad-frequency responses. The slot, with interdigital shape in the DGS, is designed to obtain dual-frequency responses and transmission zeros are introduced to split both passbands into two. The equivalent-circuit model is derived for the filter. A filter with four passbands centring at 1.74, 2.09, 2.75 and 3.14 GHz is shown with a stopband attenuation greater than 20 dB over the frequency range from 3.38 to 7.70 GHz.
Keywords :
band-pass filters; defected ground structures; equivalent circuits; microstrip filters; microwave filters; DGS slot structure; defected ground structure; dual-plane microstrip; equivalent-circuit model; frequency 1.74 GHz; frequency 2.09 GHz; frequency 2.75 GHz; frequency 3.14 GHz; frequency 3.38 GHz to 7.70 GHz; quad-band bandpass filter; quad-frequency response; stopband attenuation; transmission zero;
Journal_Title :
Electronics Letters
DOI :
10.1049/el.2010.0618
