Dual-Transmission-Line Microstrip Equiripple Lowpass Filter with Sharp Roll-Off

ETRI Journal

关键词: transmission line;    microstrip;    Lowpass filter;   

Others  :  1186041
DOI  :  10.4218/etrij.11.0210.0497

【 摘 要 】

A novel application of a dual-transmission line is proposed to design a lowpass filter (LPF). The proposed structure uses only transmission line elements to produce an equiripple LPF response with sharp roll-off. Design equations are derived using a lossless transmission line model. Controlling the electrical lengths, three transmission-zeros are realized in the stopband to obtain a sharp roll-off rate and wide stopband bandwidth. A single unit microstrip LPF with a 3-dB cut-off frequency at 1.0 GHz having a roll-off of 135 dB/GHz along with a stopband bandwidth of 69.5% is designed for validation.

   

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