一种基于传输线理论的新型GHz共模噪声抑制电路

基于传输线理论提出一种新型GHz宽阻带共模噪声抑制电路。利用双线传输线模型建立奇、偶模等效电路,在宽频带范围内准确预测了该电路结构的性能。实验结果表明:在1.9-4.5GHz频段内共模噪声抑制深度超-10dB,共模阻带相对带宽达81%;在dc-6GHz频段内差模插损小于3dB且差模信号群时延抖动较小,表明该结构可以很好地保证差模信号传输的信号完整性,性能优良。

Novel GHz Common-Mode Suppression Circuit Based on Transmission Line Theory

In this paper, a novel GHz wideband common-mode suppression circuit based on transmission line theory has been proposed. The odd even-mode equivalent circuits have been built by using two-wire transmission line model, which predict the circuit performance well in a wide frequency range. According to experiment results, the common-mode noise can be suppressed over 10 dB from 1.9 to 4.5 GHz with 81% fractional bandwidth while the insertion loss of differential-mode can be kept less 3dB from dc to 6 GHz. Also, the group delay for the differential-mode is constant within the broad frequency range. It is important that the proposed common-mode suppression circuit can keep good signal integrity of the digital differential signals due to its all-pass characteristic.