Noise reduction of bended differential transmission lines using compensation capacitance

In this paper, a novel technique to reduce the common mode noise of bended differential transmission lines is proposed. To this end, open circuited transmission lines are employed to compensate the undesirable capacitance of the bends. This method can remarkably decrease the differential to common mode conversion ratio in a very wide frequency range while offering an acceptable level of input return loss compared to un-compensated bended differential transmission lines. To present the effectiveness of this technique, time domain simulations have also been performed which show high level of common mode noise reduction offered by this method. This technique is examined on the right angle and 45 degree bended differential lines implemented inside microstrip and stripline structures.