使用用户指定的恒定阻抗、导纳、电抗和电纳圆绘制简单的 Smith 图 matlab代码.rar

function smith(z0, rcircles, xcircles, gcircles, bcircles) %SMITH Draw a Smith chart. % SMITH(Z0, RCIRCLES, XCIRCLES, GCIRCLES, BCIRCLES) has the following % parameters: % - Z0: the normalising impedance (default 1 Ohm), % - RCIRCLES: the constant resistance circles to be drawn, % - XCIRCLES: the constant reactance circles to be drawn, % - GCIRCLES: the constant conductance circles to be drawn, and % - BCIRCLES: the constant susceptance circles to be drawn. % The circles will be normalised to Z0. If no arguments are given, a % default Smith Chart will be plotted. % % Examples: % smith % smith(50) % smith(1, [ 1/3 1 3 ], [ -3 -1 -1/3 1/3 1 3 ]) % smith([], [], [], [ 1/3 1 3 ], [ -3 -1 -1/3 1/3 1 3 ]) % smith(1, [ 1/3 1 3 ], [ -3 -1 -1/3 1/3 1 3 ], ... % [ 1/3 1 3 ], [ -3 -1 -1/3 1/3 1 3 ]) % smith(1, [], [ 1/3 1 3 ], [], [ -3 -1 -1/3 ]) % % See also: smith_circles.m % Check the number of inputs. error(nargchk(0, 5, nargin)); % Set the default circles. if nargin < 3 xcircles = []; end if nargin < 4 gcircles = []; end if nargin < 5 bcircles = []; end if nargin == 0 % The default Smith Chart. z0 = 1; rcircles = [ 1/3 1 3 ]; xcircles = [ -3 -1 -1/3 1/3 1 3 ]; elseif nargin == 1 % The default Smith Chart normalised to the specified z0. rcircles = z0*[ 1/3 1 3 ]; xcircles = z0*[ -3 -1 -1/3 1/3 1 3 ]; end if isempty(z0) z0 = 1; end % Normalise the circles for plotting rvalues = rcircles/z0; xvalues = xcircles/z0; gvalues = gcircles*z0; bvalues = bcircles*z0; % A Smith Chart does not have the standard x and y axes that are used in % a Matlab plot. set(gca, 'XTick', []) % Remove the x-axis labels. set(gca, 'YTick', []) % Remove the y-axis labels. set(gca, 'XColor', 'w') % Remove the x-axis. set(gca, 'YColor', 'w') % Remove the y-axis. axis([ -1.1 1.1 -1.1 1.1 ]) % Make sure the labels are inside the axes. % This will make the figure boundary square so that the Smith Chart is a % circle rather than an elipse. axis('square') hold on % Draw the constant conductance and susceptance circles. Draw them first % so that the constant resistance and reactance circles are plotted over % them. smith_circles(-[ gvalues./(gvalues + 1) (1 + j./bvalues) ], ... abs([ 1./(gvalues + 1) 1./bvalues ]), 'y--'); % Draw the horizontal line. plot([ -1 1 ], [ 0 0 ], 'y'); % Add the r = 0 circle if not already present to draw the boundary of the % Smith Chart. if (size(rvalues, 2) == 0) || (min(abs(rvalues) ~= 0)) rvalues = [ 0 rvalues ]; end % Draw the constant resistance and reactance circles. smith_circles([ rvalues./(rvalues + 1) (1 + j./xvalues) ], ... abs([ 1./(rvalues + 1) 1./xvalues ]), 'y'); % Label the circles. Use the constant resistance and reactance circles % unless they are not plotted. if size(rcircles, 2) > 0 % Label the constant resistance circles. xpos = (rcircles - z0)./(rcircles + z0); h = text(xpos', zeros(size(xpos')), num2str(rcircles', 2)); set(h, 'VerticalAlignment', 'top', 'HorizontalAlignment', 'center'); % Label zero and infinity. h = text(-1, 0, '0'); set(h, 'VerticalAlignment', 'middle', 'HorizontalAlignment', 'right'); h = text(1, 0, '\infty'); set(h, 'VerticalAlignment', 'middle', 'HorizontalAlignment', 'left'); else % Label the constant conductance circles. xpos = (1 - gcircles*z0)./(1 + gcircles*z0); h = text(xpos', zeros(size(xpos')), num2str(gcircles', 2)); set(h, 'VerticalAlignment', 'top', 'HorizontalAlignment', 'center'); % Label zero and infinity. h = text(-1, 0, '\infty'); set(h, 'VerticalAlignment', 'middle', 'HorizontalAlignment', 'right'); h = text(1, 0, '0'); set(h, 'VerticalAlignment', 'middle', 'HorizontalAlignment', 'left'); end if size(xcircles, 2) > 0 % Label the constant reactance circles. pos = (j*xcircles + z0)./(j*xcircles - z0); xpos = real(pos'); ypos = imag(pos'); h = text(xpos, ypos, [ num2str(xcircles', 2) 'j'*ones(size(xpos)) ]); set(h, 'VerticalAlignment', 'middle', 'HorizontalAlignment', 'center'); set(h(xpos > 0), 'HorizontalAlignment', 'left'); set(h(xpos < 0), 'HorizontalAlignment', 'right'); set(h(ypos > 0), 'VerticalAlignment', 'bottom'); set(h(ypos < 0), 'VerticalAlignment', 'top'); else % Label the constant reactance circles. pos = (1 + j*z0*bcircles)./(1 - j*z0*bcircles); xpos = real(pos'); ypos = imag(pos'); h = text(xpos, ypos, [ num2str(bcircles', 2) 'j'*ones(size(xpos)) ]); set(h, 'VerticalAlignment', 'middle', 'HorizontalAlignment', 'center'); set(h(xpos > 0), 'HorizontalAlignment', 'left'); set(h(xpos < 0), 'HorizontalAlignment', 'right'); set(h(ypos > 0), 'VerticalAlignment', 'bottom'); set(h(ypos < 0), 'VerticalAlignment', 'top'); end