1. 特性阻抗：Z0〔Ω〕和静电电容：C〔pF/m〕a静电电容和特性阻抗成反比关系(同轴电缆的实际测量例：参照下表)一般同一绝缘体材料时，Z0决定于导体直径(d)和绝缘体外径(D)之比(D/d)。
1. Impedance (Z0), Capacitance (C)1)Impedance & Capacitance have an inverse proportionrelationship. (An example data on coaxial cable is illustrated below).Fundamentally, if the insulating material is exactly the same, the ratio of Z0to C is determined by the diameter ofs Z0Z0在频率大约为10MHz以上时趋于稳定。
对于同轴电缆规定10MHz时的Z0，对于同轴之外的其它电缆，定义频率或测量法后规定Z0。
Z0is stable when frequency gets to about 10 MHz & over. Coaxial cable regulates the Z0at 10 MHz, & cables other than coaxial regulate the Z0by defining frequency or measurement method.d与介电常数( ε )的关系除D/d、频率外，决定Z0和C的要素还有介电常数( ε )。
这取决于绝缘体材料。
导体为同一时，ε 和Z0、C的关系如q、w。
q绝缘体外径不变，缩小ε时，→C变小，Z0增大(即可不改变结构尺寸地改变C和Z0)w C和Z0不变，缩小ε 时，→绝缘体外径变小(即可不改变C和Z0地缩小外径)一般来说PVC是受频率和温度影响ε 大幅度变化的绝缘材料。
因此，对Z0等电气特性的要求高时，应使用聚烯烃类、氟化乙烯树脂类等ε稳定的绝缘体材料。
3)The relationship of dielectric contact (ε).Another factor for determining Z0& C, besides D/d & frequency is dielectric contact (ε).This is determined according to the insulating material.q&w below show the relationship between ε, Z0& C when the conductors used are same size.q When the external diameter of the insulating body is not changed & εis made smaller→ C becomes smaller & Z0becomes bigger.(In other words : without changing the size of thestructure, C & Z0can be changed.)w When C & Z0are not changed, & εis made smaller→the external diameter of the insulating bodybecomes smaller.(In other words : without changing C & Z0, theexternal diameter of the insulating body can bemade smaller.)In general PVC is an insulating material where unfortunately εexperiences large scale changes, according to frequency & temperature. Because of this, when electrical properties of Z0etc, are demanded polyoefin & fluorocarbon polymers etc. are used in the insulating material to stabilize ε.〔补充说明：同轴电缆之外的Z0和C〕即便是同一电缆，接线方法(信号传输方式)不同，Z0和C也大不相同。
(阻抗匹配电缆的实际测量例：参照下表)[Additional information on the Z0& C in cable other than coaxial cable.]Even if the cable is the same, Z0and C can be very different by wiring.(An example of a survey on impedance matching cable is illustrated below).·不平衡接线：测量信号线以外的接地线(单对)及屏蔽一并接地。
测量接地〜测量信号线芯之间。
·平衡接线：测量信号线以外均为开路。
测量线对之间。
两者的关系大致如下式所示。
[不平衡接线Z0] × 1.4~1.6 Լ [平衡接线Z0]2. 延迟时间：Td [ns/m]如果没有绝缘体(导体伸展于空中) ，信号将以光速传输。
但是，电线中有绝缘体，所以信号不是以光速来传输。
(介电常数：ε的影响）在电线中，信号传输的时间称为延迟时间。
ε和Td的关系如下表所示。
但除特殊用途之外，Td的绝对值不会成为问题。
·Unbalanced wiring : All GND wires, with the exception of the measured signal wire, & the shield are bundled together to earth. Measurement is between earth & the measured signal wire.·Balanced wiring : With the exception of the measured signal pair, everything is open. Measurement is between pairs.The relationship of both of the above is approximately shown in the equation below :[Unbalanced wiring Z0] × 1.4~1.6Լ[Balanced wiring Z0]2. Time delay : Td [ns/m]If there is no insulating body (when the conductor is an overhead cable - stretched up in the air) the signal is transmitted at light velocity. However, when the cable is insulated, the signal is not transmitted at light velocity.(Dielectric contact : εinfluence).The time taken for the cable to transmit the signal is called the ‘time delay’ (Td.)The relationship between this ε& Td is as below :But, except in particular uses, the absolute value of Td is nota problem.εTd 大小大小εTd big smallbig small3. 衰减量：α[dB/L] (L：试样长度)用电缆传输信号时，因结构和电气特性上的能量损失，输出信号会比输入信号弱。
α 就是表示输入和输出之比。
同一电缆时，基本上与长度成正比，且频率越高α 越大，尤其是在远距离、高频条件下使用时大多会出现问题。
3. Attenuation : α [dB/L] (L : absolute length)When a signal is transmitted by a cable, because of the energy loss related to the structure & electrical properties ;the output signals become weak. The input/output ratio is shown as : α.With the same cable, basically because in proportion to its length, the higher the wavelength becomes the bigger αbecomes, there are many problems when particularly long distances & high frequencies are used.1000100101101001000频率Frequency [MHz]衰减量 [ d B / k m ]50Ω同轴电缆的实际测量例An example of a survey on 50Ω coaxial cable.A t t e n u a t i o n。