卷绕型带状脉冲形成线的特性阻抗

 设计了一种全固态、低阻抗、卷绕型零厚度带状脉冲形成线。通过保角变换将其特性阻抗的计算转化为对非对称型平板带状线特性阻抗的计算，并得出了卷绕型带状线特性阻抗的计算方法。数值模拟结果表明:带状线不对称将使带状线的特性阻抗减小，但当内导体宽与上下外导体间距之比很大时，可忽略不对称带来的影响。给出了不对称度（内导体分别到上下外导体的距离之比）对特性阻抗的影响关系，且不对称度小于3.1时，特性阻抗的变化小于5％，在实际工程设计中可忽略不对称带来的影响。

Characteristic resistance of convolute strip pulse forming line

A convoluted strip pulse forming line with zero thickness trace has been designed, which is all-solid and has low characteristic impedance. Through conformal mapping, the calculation method of its characteristic impedance the impedance is derived by converting the convoluted stripline into an asymmetric one. The simulation shows that the impedance will decrease because of trace offset, while the influence of asymmetry could be ignored when the ratio of trace width to the separation between ground planes is large enough. The relationship between asymmetric rate(the distance ratio of trace-upper plane to trace-lower plane) and the impedance is obtained. And the impedance will fluctuate within 5% when the rate less than 3.1, so the influence of asymmetry could be ignored in practical design