www.pudn.com > loopantenna.rar > efield2.m, change:2002-04-17,size:1860b


%EFIELD2 Radiated/scattered field over a large sphere 
%   Uses the mesh file from RWG2, mesh2.mat, and 
%   the file containing surface current coefficients, 
%   current.mat, from RWG4 as inputs. 
% 
%   Uses the structure sphere.mat/sphere1.mat to display  
%   radiation intensity distribution over the sphere surface.  
%   The sphere doesn't intersect the radiating object. 
% 
%   The following parameters need to be specified: 
%    
%   Sphere radius (m) 
% 
%   Copyright 2002 AEMM. Revision 2002/03/11  
%   Chapter 3 
 
clear all 
%Load the data 
load('mesh2'); 
load('current'); 
load('sphere'); 
 
p=100*p;    %sphere radius is 100 m 
 
k=omega/c_; 
K=j*k; 
 
for m=1:EdgesTotal 
    Point1=Center(:,TrianglePlus(m)); 
    Point2=Center(:,TriangleMinus(m)); 
    DipoleCenter(:,m)=0.5*(Point1+Point2); 
    DipoleMoment(:,m)=EdgeLength(m)*I(m)*(-Point1+Point2);  
end 
 
TotalPower=0; 
%Sphere series 
M=length(t); 
for m=1:M 
    N=t(1:3,m); 
    ObservationPoint=1/3*sum(p(:,N),2); 
    [E,H]=point(ObservationPoint,eta_,K,DipoleMoment,DipoleCenter); 
    ET=sum(E,2); HT=sum(H,2); 
    Poynting(:,m)=0.5*real(cross(ET,conj(HT))); 
    U(m)=(norm(ObservationPoint))^2*norm(Poynting(:,m));     
    Vector1=p(:,N(1))-p(:,N(2)); 
    Vector2=p(:,N(3))-p(:,N(2)); 
    Area =0.5*norm(cross(Vector1,Vector2));  
    TotalPower=TotalPower+norm(Poynting(:,m))*Area; 
    %------------------------------ 
    X(1:3,m)=[p(1,N)]'; 
    Y(1:3,m)=[p(2,N)]'; 
    Z(1:3,m)=[p(3,N)]';       
end 
 
TotalPower 
 
GainLogarithmic     =10*log10(4*pi*max(U)/TotalPower) 
GainLinear          =4*pi*max(U)/TotalPower 
RadiationResistance =2*TotalPower/abs(GapCurrent)^2 
 
FileName='gainpower.mat';  
save(FileName, 'TotalPower','GainLogarithmic','GainLinear'); 
 
U=U/norm(U); 
C=repmat(U,3,1); 
h=fill3(X,Y,Z,C); 
colormap gray; 
axis('equal') 
rotate3d on