[讨论]请问波阻抗有什么用?

波阻抗, 是对于传输TE ,TM的单导体（例如波导）而言， 特性阻抗是对传输tem波的双导体而言，两者都是为了匹配而言，一个是场 一个是路的

特性阻抗與入射電流及電壓有關,且是傳導線的几何結構及充填材料的函數. 可以說Zo=V/I L9lNAiOH  
波阻抗與橫向電場及磁場有關,且只與材質的常數有關,可以說是波Z=E/H(橫向分量)

引用第11楼alai318于2008-10-25 10:48发表的 : T%[&[8{8  
特性阻抗與入射電流及電壓有關,且是傳導線的几何結構及充填材料的函數. 可以說Zo=V/I fZq_]1(/uP  
波阻抗與橫向電場及磁場有關,且只與材質的常數有關,可以說是波Z=E/H(橫向分量)

B-R& v8F  
that's right great

在研究空间波传输的时候用到波阻抗，与介电常数和磁导率有关;而特性阻抗指传输线的阻抗特性,只与传输线的L和C有关。表达式都不一样。

我认为波阻抗是讨论空间啊，介质啊电磁波传播的时候用的，涉及到电路时，多用的是特性阻抗

看看特征阻抗的定义： 7mBH#Q)  
characteristic impedance Symbol,  Z0.  1. Theoretically, the impedance that would be simulated by a given two-conductor or coaxial line of uniform construction, if that line were of infinite length. This value is determined by the materials used for the two conductors, the dielectric used to insulate the two conductors, the diameters of the conductors, and the spacing between them. 2. In practice, for a transmission line or waveguide terminated with a load that produces no standing waves on the line, the ratio of radio-frequency (RF) voltage to RF current. This ratio is the same at all points along the length of a perfectly matched line, and depends on the physical construction of the line. Coaxial lines typically have Z0 between 50 and 100 ohms. Twinlead is available with 75-ohm and 300-ohm  Z0 values. Open-wire line has  Z0 between 300 and 600 ohms, depending on the spacing between the conductors, and also on the type of dielectric (insulating material) employed to keep the spacing constant between the conductors. 3. Experimentally, the value of impedance that, if it terminates a transmission line or waveguide, results in no reflected power from the load end of line. This is always a pure resistance; that is, it contains no reactance.

再把梁昌洪的《微波技术讲义》中关于波阻抗的说明贴出来 Xx?~%o6  
波中出现了阻抗概念，它与R、L、C的低频阻抗有所不同。衡量电磁波的反射和传输，我们引入了反射系数和波阻抗,波阻抗η与媒质特性相关。换句话说，媒质的变化影响波的传输。没有反射条件，并不一定是相同的媒质，而只要求两者波阻抗相等。这一思想是波(不仅仅是电磁波)研究中的一个飞跃。吃透这一思想的竟是一个著名的科幻小说家——凡尔纳，他根据这一原理，首先写出了脍炙人口的《隐身人》。

比较一下，就明白了两个概念的不同： xdh%mG:?  
tLcw?aB  
衡量电磁波的反射和传输 <---------------> Theoretically, the impedance that would be simulated by a given two-conductor or coaxial line of uniform construction,In practice, for a transmission line or waveguide terminated with a load that produces no standing waves on the line, the ratio of radio-frequency (RF) voltage to RF current. This ratio is the same at all points along the length of a perfectly matched line, and depends on the physical construction of the line

引用第4楼monster528于2008-08-11 09:00发表的 : nxx/26{  
tem波时确实不等值。 zH6@v+gb  
只是不知道波阻抗的概念有什么用？ ;,e16^\' &  
似乎一般使用的都是特性阻抗和输入阻抗的概念。

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波阻抗用处很多，例如： GN9kCyPK  
当用横向谐振法研究多层材料特性，即把传输线理论应用于多层介质的反射特性研究时，波阻抗可等价为特性阻抗。 uwr7 .\7  
另外，研究天线的辐射场要用到波阻抗。