一种低成本宽带共模滤波器

摘要

针对周期性缺陷地结构( DGS)滤波器面积大的问题，提出一种采用多谐振点滤波的低成本实现方法。首先分析了哑铃型DGS不同位置尺寸的变化对其等效电感参数的影响，然后选取合适的尺寸参数以获得合适的不同共模滤波器谐振频点，最后通过组合滤波拓宽差分信号共模滤波器的阻带范围，并可获得较好的阻带抑制深度。 HFSS仿真验证结果表明，该结构的差模信号损耗很小，并且其-20 dB共模阻带范围为4.1~7.3 GHz。与周期性DGS相比，该方法在相同共模噪声抑制深度下具有面积缩小约40%、阻带宽度增加50%等优点。%To solve the problem that the area of periodic Defected Ground Structure( DGS) is larger, a no-vel low-cost wideband common-mode filter in high-speed differential signals is proposed which utilizes multiply resonant frequency points. The effect of equivalent inductance parameter is analyzed by adjusting the size of dumbbell firstly. And the applicable resonant frequency points of common-mode filter are ob-tained by selecting right size parameter . Finally, the broaden stopband bandwidth is achieved with the help of combinatorial common-mode filters, which is efficient in suppressing the common-mode noise. HFSS software simulation results show that the differential signal is nearly intact, and the common-mode noise can be reduced over 20 dB from 4. 1 GHz to 7. 3 GHz. Compared with the periodic DGS at the same suppression depth of common-mode noise, the proposed method has the advantages that surface area is re-duced by about 40% and the stopband width is increased by 50%.