Suppressing Non-Ideal Resonance in Defected Ground Structure Based on Grounded Coplanar Waveguide

In this paper, a new method is proposed and verified to eliminate the non-ideal resonance caused by DGS application in GCPW by adding via holes to reduce electromagnetic leakage. By adding a dense through-hole array around the dumbbell DGS can form an electrical wall to confine the electromagnetic to the central conductor. The test results show that the non-ideal resonance is eliminated after adding the through hole and a wide stopband from 16.1 GHz to 17.8 GHz with rejection larger than 20 dB. A double-dumbbell bandpass filter was successfully designed with this tech eliminating the non-ideal resonance at 8.053 GHz and 14.232 GHz. The results show that this structure can effectively eliminate the irrational resonance caused by electromagnetic leakage.