Hybrid Microstrip T-Stub/Defected Ground Structure Cell for Electromagnetic Interference Bandpass Filter Design

作者：Luo, Xun^*; Ma, Jian-Guo; Li, Er-Ping; Ma, Kaixue

来源：IEEE Transactions on Electromagnetic Compatibility, 2011, 53(3): 717-725.

DOI：10.1109/TEMC.2011.2114667

• Bandpass filter
• broadside-coupled (BC) transition
• electromagnetic interference (EMI)
• hybrid microstrip T-stub/defected ground structure (HMT/DGS) cell
• interdigital-coupled scheme
• wide stopband

In this paper, the hybrid microstrip T-stub/defected ground structure (HMT/DGS) cell is presented, which is composed of a microstrip T-stub and an interdigital DGS with the broadside-coupled (BC) transition. Finely adjusted resonance can be achieved by the proposed cell. Meanwhile, strong slow-wave effect is employed by the structure, which leads to wide stopband responses. Based on these HMT/DGS cells, the interdigital-coupled scheme is employed to implement the electromagnetic interference (EMI) bandpass filter with high performance. To verify the aforementioned mechanism, two filters are designed and fabricated. Specifically, the second-order bandpass filter with a fractional bandwidth (FBW) of 14.3% has a 29.1-dB stopband rejection up to 15f(0) (where f(0) stands for the passband center frequency). The fourth-order bandpass filter with an FBW of 10.8% demonstrates a 30.1-dB stopband rejection up to 12.1f(0). Both types of filters show compact sizes with low insertion losses less than 1.1 dB.

• 出版日期2011-8
• 单位天津大学; 浙江大学; 电子科技大学