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function [E_theta,E_phi,Prad,Dmax] = AnalyzeNF2FF( Sim_Path, nf2ff, f, theta, phi, r )
% [E_theta,E_phi,Prad,Dmax] = AnalyzeNF2FF( Sim_Path, filenames_E, filenames_H, f, theta, phi, r )
%
% calculates the farfield via a near field to far field transformation
%
% input:
% Sim_Path: simulation directory
% nf2ff: structure on filenames etc. as created by CreateNF2FFBox
% f: frequency (Hz) for far field calculation
% theta: (degrees) vector of discrete theta values to calculate the far field for
% phi: (degrees) vector of discrete phi values to calculate the far field for
% r: (optional) Radius (m) at which the E-fields are calculated (default: 1 m)
%
% output:
% E_theta: E_theta(theta,phi); theta component of the electric field strength at radius r
% E_phi: E_phi(theta,phi); phi component of the electric field strength at radius r
% Prad: time averaged radiated power
% Dmax: maximum directivity
%
% example:
% see examples/NF2FF/infDipol.m
%
% See also CreateNF2FFBox
%
% (C) 2010 Sebastian Held <sebastian.held@gmx.de>
% (C) 2011 Thorsten Liebig <thorsten.liebig@gmx.de>
% check arguments
error( nargchk(6,6,nargin) );
if ~isscalar(f)
error 'Currently only one frequency is supported. Call this function multiple times.'
end
warning('openEMS:AnalyzeNF2FF','This function is deprecated, use CalcNF2FF instead');
filenames_E = nf2ff.filenames_E;
filenames_H = nf2ff.filenames_H;
if (~isrow(nf2ff.directions))
nf2ff.directions = nf2ff.directions';
end
% read time domain field data and transform into frequency domain
for n=find(nf2ff.directions==1)
[Ef{n}, E_mesh{n}] = ReadHDF5Dump( [Sim_Path '/' filenames_E{n} '.h5'], 'Frequency', f );
if (Ef{n}.FD.frequency(1) ~= f)
error 'frequency mismach'
end
%clear out time domain data
if isfield(Ef{n},'TD')
Ef{n} = rmfield(Ef{n},'TD');
end
[Hf{n}, H_mesh{n}] = ReadHDF5Dump( [Sim_Path '/' filenames_H{n} '.h5'], 'Frequency', f );
%clear out time domain data
if isfield(Hf{n},'TD')
Hf{n} = rmfield(Hf{n},'TD');
end
% reshape mesh into row vector
mesh{n}.x = reshape( E_mesh{n}.lines{1}, 1, [] );
mesh{n}.y = reshape( E_mesh{n}.lines{2}, 1, [] );
mesh{n}.z = reshape( E_mesh{n}.lines{3}, 1, [] );
end
% create a normal vector for every plane
% FIXME!!! this is dependent upon the order of filenames_*
n = {};
for a=1:6
temp = [(a<=2), ((a>=3)&&(a<=4)), (a>=5)];
n{a} = temp - 2*mod(a,2)*temp;
end
physical_constants
k = 2*pi*f/c0;
center = [0 0 0];
Umax = 0;
phi_idx = 0;
for phi_deg_aufpunkt = phi
phi_rad_aufpunkt = phi_deg_aufpunkt/180*pi; % radiant
phi_idx = phi_idx + 1;
theta_idx = 0;
for theta_deg_aufpunkt = theta
theta_rad_aufpunkt = theta_deg_aufpunkt/180*pi; % radiant
theta_idx = theta_idx + 1;
N_theta = 0;
N_phi = 0;
L_theta = 0;
L_phi = 0;
for a=find(nf2ff.directions==1)
[N_theta_,N_phi_,L_theta_,L_phi_] = process_plane( k, n{a}, center, mesh{a}, Ef{a}.FD.values{1}, Hf{a}.FD.values{1}, theta_rad_aufpunkt, phi_rad_aufpunkt );
N_theta = N_theta + N_theta_; N_phi = N_phi + N_phi_;
L_theta = L_theta + L_theta_; L_phi = L_phi + L_phi_;
end
% E-fields
erg_E_theta = -1i*k*exp(-1i*k*r) / (4*pi*r)*(L_phi+Z0*N_theta);
erg_E_phi = 1i*k*exp(-1i*k*r) / (4*pi*r)*(L_theta-Z0*N_phi);
% output
E_theta(theta_idx,phi_idx) = erg_E_theta;
E_phi(theta_idx,phi_idx) = erg_E_phi;
% directivity
U = r^2/(2*Z0) * sum(abs([erg_E_theta erg_E_phi]).^2);
Umax = max( [Umax U] );
end
end
% power
Prad = 0;
for a=find(nf2ff.directions==1)
[~,~,~,~,P] = process_plane( k, n{a}, center, mesh{a}, Ef{a}.FD.values{1}, Hf{a}.FD.values{1}, theta_rad_aufpunkt, phi_rad_aufpunkt );
Prad = Prad + P;
end
% directivity
Dmax = 4*pi*Umax / Prad;
% integrate over one plane
function [N_theta,N_phi,L_theta,L_phi,Prad] = process_plane( k, n, center, mesh, E_field, H_field, theta_rad_aufpunkt, phi_rad_aufpunkt )
% [N_theta,N_phi,L_theta,L_phi,Prad] = process_plane( k, n, center, mesh, E_field, H_field, theta_rad_aufpunkt, phi_rad_aufpunkt )
%
% k: wave number
% n: normal vector of the plane
% center: correction coordinates for the center of the antenna
% mesh: mesh info
% E_field: E field array ?x?x?x3
% H_field: H field array ?x?x?x3
% speed up
sin__theta_rad_aufpunkt = sin(theta_rad_aufpunkt);
cos__theta_rad_aufpunkt = cos(theta_rad_aufpunkt);
sin__phi_rad_aufpunkt = sin(phi_rad_aufpunkt);
cos__phi_rad_aufpunkt = cos(phi_rad_aufpunkt);
if abs(n(1)) == 1
% x-plane
x = mesh.x(1);
[y z] = ndgrid( mesh.y, mesh.z );
coord1 = mesh.y.';
coord2 = mesh.z.';
Ex = squeeze( E_field(1,:,:,1) );
Ey = squeeze( E_field(1,:,:,2) );
Ez = squeeze( E_field(1,:,:,3) );
Hx = squeeze( H_field(1,:,:,1) );
Hy = squeeze( H_field(1,:,:,2) );
Hz = squeeze( H_field(1,:,:,3) );
elseif abs(n(2)) == 1
% y-plane
y = mesh.y(1);
[x z] = ndgrid( mesh.x, mesh.z );
coord1 = mesh.x.';
coord2 = mesh.z.';
Ex = squeeze( E_field(:,1,:,1) );
Ey = squeeze( E_field(:,1,:,2) );
Ez = squeeze( E_field(:,1,:,3) );
Hx = squeeze( H_field(:,1,:,1) );
Hy = squeeze( H_field(:,1,:,2) );
Hz = squeeze( H_field(:,1,:,3) );
elseif abs(n(3)) == 1
% z-plane
z = mesh.z(1);
[x y] = ndgrid( mesh.x, mesh.y );
coord1 = mesh.x.';
coord2 = mesh.y.';
Ex = squeeze( E_field(:,:,1,1) );
Ey = squeeze( E_field(:,:,1,2) );
Ez = squeeze( E_field(:,:,1,3) );
Hx = squeeze( H_field(:,:,1,1) );
Hy = squeeze( H_field(:,:,1,2) );
Hz = squeeze( H_field(:,:,1,3) );
end
Jx = n(2) .* Hz - n(3) .* Hy;
Jy = n(3) .* Hx - n(1) .* Hz;
Jz = n(1) .* Hy - n(2) .* Hx;
Mx = -n(2) .* Ez + n(3) .* Ey;
My = -n(3) .* Ex + n(1) .* Ez;
Mz = -n(1) .* Ey + n(2) .* Ex;
r_cos_psi = x*sin__theta_rad_aufpunkt*cos__phi_rad_aufpunkt + y*sin__theta_rad_aufpunkt*sin__phi_rad_aufpunkt + z*cos__theta_rad_aufpunkt;
e_fkt = exp( +1i*k*r_cos_psi );
N_theta = dbltrapz( ( Jx*cos__theta_rad_aufpunkt*cos__phi_rad_aufpunkt + Jy*cos__theta_rad_aufpunkt*sin__phi_rad_aufpunkt - Jz*sin__theta_rad_aufpunkt) .* e_fkt, coord1, coord2 );
N_phi = dbltrapz( (-Jx*sin__phi_rad_aufpunkt + Jy*cos__phi_rad_aufpunkt) .* e_fkt, coord1, coord2 );
L_theta = dbltrapz( ( Mx*cos__theta_rad_aufpunkt*cos__phi_rad_aufpunkt + My*cos__theta_rad_aufpunkt*sin__phi_rad_aufpunkt - Mz*sin__theta_rad_aufpunkt) .* e_fkt, coord1, coord2 );
L_phi = dbltrapz( (-Mx*sin__phi_rad_aufpunkt + My*cos__phi_rad_aufpunkt) .* e_fkt, coord1, coord2 );
if nargout > 4
% Prad requested
% this is crap! recode it!
EH = zeros(size(Ex));
for i1 = 1:numel(coord1)
for i2 = 1:numel(coord2)
E = [Ex(i1,i2) Ey(i1,i2) Ez(i1,i2)];
H = [Hx(i1,i2) Hy(i1,i2) Hz(i1,i2)];
EH(i1,i2) = real( dot(cross(E,conj(H)),n) );
end
end
Prad = 0.5 * dbltrapz( EH, coord1, coord2 );
end
function Q = dbltrapz(matrix,a,b)
%DBLTRAPZ Trapezoidal numerical integration in two dimensions.
% Z = DBLTRAPZ(MATRIX,A,B) computes an approximation of the double integral
% of MATRIX via the trapezoidal method (with respect to A and B). A and B must be
% column vectors of the same length.
% index like this: MATRIX(A,B)
if nargin < 3, error('MATLAB:dblquad:NotEnoughInputs',...
'Requires at least three inputs.'); end
if size(a,2) ~= 1, error('column vectors required'); end
if size(b,2) ~= 1, error('column vectors required'); end
temp = zeros(size(b));
for i = 1:length(b)
temp(i) = trapz( a, matrix(:,i) );
end
Q = trapz( b, temp );
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