一个公式教你背会 矩形波导或圆波导(或者矩形或圆形谐振腔)以纵向分量为领矢得到全部的场表达式

看不懂的我抽空来补充完整
开心!!之前这个我一直没背下来,现在摸到石头边了



以纵向分量为领向矢量

[left[ egin{array}{cccc} E_{u}\ E_{v}\ H_{u}\ H_{v} end{array} ight ]= frac{1}{K_c^2} left[ egin{array}{cccc} -gamma& 0 & 0 & {-jomegamu}\ 0& -gamma &jomega mu &0\ 0& jomegaepsilon &-gamma&0 \ -jomega epsilon& 0 &0 &-gamma end{array} ight ] left[ egin{array}{cccc} frac{partial E_z}{h_1partial u}\ frac{partial E_z}{h_2partial v}\ frac{partial H_z}{h_1partial u} \ frac{partial H_z}{h_2partial v} end{array} ight ] ]

矩形波导的情况就是

[u=x,quad v=y\ h_1=1,quad h_2=1 ]

圆波导的情况就是

[u=r,quad v=varphi\ h_1=1,quad h_2=r ]

波导,纵向分量为领向矢量

矩形波导(TE_{mn})

[H_z=H_0cos(frac{mpi}{a}x)cos(frac{npi}{b}y)e^{-jeta z}\ E_z=0 ]

矩形波导(TM_{mn})

[E_z=E_0sin(frac{mpi}{a}x)sin(frac{npi}{b}y)e^{-jeta z}\ H_z=0 ]

圆波导(TE_{mn})

[H_z=H_0J_m(K_cr)mathop{}limits_{sin(mvarphi)}^{cos(mvarphi)}e^{-jeta z}\ E_z=0 ]

圆波导(TM_{mn})

[E_z=E_0J_m(K_cr)mathop{}limits_{sin(mvarphi)}^{cos(mvarphi)}e^{-jeta z}\ H_z=0 ]






如果是谐振腔的话公式也很像。
4个(-gamma)都变成 (frac{partial}{partial z})

[left[ egin{array}{cccc} E_{u}\ E_{v}\ H_{u}\ H_{v} end{array} ight ]= frac{1}{K_c^2} left[ egin{array}{cccc} frac{partial}{partial z}& 0 & 0 & {-jomegamu}\ 0& frac{partial}{partial z} &jomega mu &0\ 0& jomegaepsilon &frac{partial}{partial z}&0 \ -jomega epsilon& 0 &0 &frac{partial}{partial z} end{array} ight ] left[ egin{array}{cccc} frac{partial E_z}{h_1partial u}\ frac{partial E_z}{h_2partial v}\ frac{partial H_z}{h_1partial u} \ frac{partial H_z}{h_2partial v} end{array} ight ] ]

谐振腔,纵向分量为领向矢量

矩形谐振腔,(TM_{mnp})

[E_z=2E_0sin(frac{mpi}{a}x)sin(frac{npi}{b}y)cos(frac{ppi}{l}z)\ H_z=0 ]

矩形谐振腔,(TE_{mnp})

[H_z=-2j H_0cos(frac{mpi}{a}x)cos(frac{npi}{b}y)sin(frac{ppi}{l}z)\ E_z=0 ]

圆形谐振腔,(TM_{mnp})

[E_z=2E_0 J_m(K_c r)mathop{}limits_{sin(mvarphi)}^{cos(mvarphi)}cos(frac{ppi}{l}z)\ H_z=0 ]

圆形谐振腔,(TE_{mnp})

[H_z=-2j H_0 J_m(K_c r)mathop{}limits_{sin(mvarphi)}^{cos(mvarphi)}sin(frac{ppi}{l}z)\ E_z=0 ]

其他的

另一个有意思的是Lorentz变换矩阵,虽然用的频率低,但是结构很漂亮

[left(egin{array}{c} x \ y \ z \ i c t end{array} ight)=left(egin{array}{cccc} gamma & 0 & 0 & i eta gamma \ 0 & 1 & 0 & 0 \ 0 & 0 & 1 & 0 \ -i eta gamma & 0 & 0 & gamma end{array} ight)left(egin{array}{c} x^{prime} \ y^{prime} \ z^{prime} \ i c t^{prime} end{array} ight) ]

其中,

[eta:=frac{u}{c}, quad gamma:=frac{1}{sqrt{1-eta^{2}}} ]

Lorentz矩阵是个正交矩阵,(A^{-1}=A^T)

原文地址:https://www.cnblogs.com/yhm138/p/14138773.html