Highly Selective Bandpass Filter Based on SIR Slot and DGS

Wei Dai ； Wusheng Ji ； Siyu Zhao ； Xiangwei Zhou

《International Core Journal of Engineering》 6卷9期 (2020/09) Pp. 86-93

https://doi.org/10.6919/ICJE.202009_6(9).0012

摘要

A highly selective bandpass filter based on SIR (Stepped Impedance Resonator) grooves and DGS (Defected Ground Structure) is designed. The filter is composed of a microstrip-slot-microstrip multilayer structure. The top and bottom microstrip structures of the circuit realize interlayer coupling through the middle layer SIR-shaped groove and spiral DGS, and the coupling efficiency is high. The working frequency of the filter is 5.26- 6.40GHz, the center frequency is 5.83GHz, and the fractional bandwidth is 19.6%; the filter insertion loss S21 is better than -1.5dB, the return loss S11 is better than -14.5dB, and the lower stopband is 4.3GHz and There is a transmission zero at the upper stopband at 7.2GHz, the stopband cut-off edge is relatively steep, and it has good in-band performance and frequency selectivity.

關鍵字

Bandpass filter ； Multi-layer interlayer coupling structure ； SIR groove ； Spiral DGS ； high selectivity

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