论文信息 - A compact common-mode filter for GHz differential signals using defected ground structure and shorted microstrip stubs

A compact common-mode filter for GHz differential signals using defected ground structure and shorted microstrip stubs

A miniaturized common-mode suppression filter for GHz differential signals is realized using two C-shaped and one Hshaped defected ground structure (DGS), and one of the C-shaped DGS units is combined with two symmetrical shorted microstrip stubs to further reduce the area occupied. The equivalent transmission line model of the DGS unit with shorted microstrip stubs is established with good agreement to the full-wave simulation. It is found that the length of the stub and resonant frequency is inversely proportional. A sample board is fabricated on FR4 substrate. It is proved that the common-mode noise can be reduced by over 15dB from 3.68GHz to 8.43GHz, and the differential signal is not affected. The filter size is about 0.29λgX 0.32λg, and the fractional bandwidth of the stopband is 78%. It is the first common-mode filter using shorted microstrip stubs with the most compact design to our best knowledge.

Zhenghe Feng | Zhenghe Feng | Yangyang Pang | Yangyang Pang

[1] K. Gupta,et al. Microstrip Lines and Slotlines , 1979 .

[2] Lin-Kun Wu,et al. Design of miniaturized common-mode filter by multilayer low-temperature co-fired ceramic , 2004, IEEE Transactions on Electromagnetic Compatibility.

[3] T. Itoh,et al. A Novel Wideband Common-Mode Suppression Filter for Gigahertz Differential Signals Using Coupled Patterned Ground Structure , 2009, IEEE Transactions on Microwave Theory and Techniques.

[4] Lin-Kun Wu,et al. Design of miniaturized common-mode filter by multi-layer low temperature co-fired ceramic , 2003 .

[5] A. Abdel-Rahman,et al. Control of bandstop response of Hi-Lo microstrip low-pass filter using slot in ground plane , 2004, IEEE Transactions on Microwave Theory and Techniques.

[6] Jae-Wook Lee,et al. Novel U-slot and V-slot DGSs for bandstop filter with improved Q factor , 2006, IEEE Transactions on Microwave Theory and Techniques.

[7] Y. Miura,et al. A new wideband common-mode noise filter consisting of Mn-Zn ferrite core and copper/polyimide tape wound coil , 2005, IEEE Transactions on Magnetics.