qsynth.m

PLLmatlab for simulink

      
       elseif topology==2
          % Rin=0, Rl=1 (Vsource input, 1 ohm load)
          % 
          m     = b(2:length(b)); % drop leading 0.0 term
          zeros = roots(m);       % 
          m2 = [];
          n2 = [];
          for i=1:length(a)  
              if rem(i,2)
                 n2=[n2,a(i),0];
              else
                 m2=[m2,a(i),0];
              end;
          end;
         
          m2=m2(1:(length(m2)-1));
          for i = 1:(n-1)/2
              % need an xmission zero @ w=wx
              wx = j*abs(zeros(2*i)); % pick an xmission zero....

              % do a partial removal of the impedance pole @ inf
              % first evaluate impedance @ w=wx
              zmag = polyval(n2,wx)/polyval(m2,wx);
              L(2*i-1) = zmag/wx;
              % this partially removes the pole

              n2 = n2-conv(m2,[L(2*i-1),0]);
              % now remaining admittance has a pole at w=wx

              % remove it by shunting a series LC
              % first must determine L & C values
              [q,r1] = deconv(n2,[1 0 abs(wx)^2]);  % r should be zero
              k = polyval(m2,wx)/polyval(conv(q,[1 0]),wx);
              L(2*i) = 1/k;
              C(2*i) = 1/(L(2*i)*(abs(wx)^2));
              [p,r2] = deconv( m2-k*conv(q,[1 0])   ,  [1 0 abs(wx)^2]);
              m2=p;
              n2=q;
          end;
          L(n)= n2(1)/m2;     % final series L .... amazing .... absolutly amazing! 
          L = fliplr(L)';     % need to reverse this network  
          C = [0,fliplr(C)]'; % 
          
       end;
       set(Hqsynth_(i_ripl),'userdata',L);
       set(Hqsynth_(i_ripv),'userdata',C);
       
       s='';
       for i=1:(length(L)-1)
           s=[s,sprintf([fmtstr,'\n'],L(i))];
       end;
       s=[s,sprintf(fmtstr,L(length(L)))];
       set(Hqsynth_(i_lv),'string',s);
       s='';
       for i=1:(length(C)-1)
           s=[s,sprintf([fmtstr,'\n'],C(i))];
       end;
       s=[s,sprintf(fmtstr,C(length(C)))];
       set(Hqsynth_(i_cv),'string',s);
    
    elseif strcmp(Action,'getLC');
      % Out1 = get(Hqsynth_(i_ripl),'userdata'); % inductors
      % Out2 = get(Hqsynth_(i_ripv),'userdata'); % capacitors
       
       % huh? ,  should get it from strings in edit fields
       caps = get(Hqsynth_(i_cv),'string'); 
       inds = get(Hqsynth_(i_lv),'string'); 
       
     
       
       for i=1:length(caps(:,1))
          Out2(i) = s2n(caps(i,:));
       end;
       
       for i=1:length(inds(:,1))
          Out1(i) = s2n(inds(i,:));
       end;
    
    
    elseif strcmp(Action,'test')
       topology = get(Hqsynth_(i_topology),'value');   % network topology
       wn = 2*pi*str2num(get(Hqsynth_(i_fcv),'string'));
       w  = 0:(wn/25):10*wn;
       [L,C]=qsynth('getLC');
       if topology ==1
          % test the synthesis 
          % begin with source resistor 
          [a,b,c,d,q]=pabcd([],[],[],[],[],'rs',1);
          % then the shunt capacitor
          [a,b,c,d,q]=pabcd(a,b,c,d,q,'cp',C(1)); 
          for i = 1:(length(L)-1)/2
              % series L
              [a,b,c,d,q]=pabcd(a,b,c,d,q,'ls',L((i*2)));
              % shunt series LC
              [a,b,c,d,q]=pabcd(a,b,c,d,q,'lcs',L((i*2)+1),C((i*2)+1));
          end;
          
       elseif topology ==2
          a = []; b = []; c = []; d = []; q = [];
          for i = 1:(length(L)-1)/2
              % series L
              [a,b,c,d,q]=pabcd(a,b,c,d,q,'ls',L((i*2-1)));
              % shunt series LC
              [a,b,c,d,q]=pabcd(a,b,c,d,q,'lcs',L((i*2)),C((i*2)));
          end;
          % finish with a series L
          [a,b,c,d,q]=pabcd(a,b,c,d,q,'ls',L(length(L)));
          % and a 1 ohm shunt R load resistor
          [a,b,c,d,q]=pabcd(a,b,c,d,q,'rp',1);
       end;
       
       % [mag,phase]   =   bode(q,a,w);
       h = freqs(q,a,w);
       set(Hqsynth_(i_pl2),'xdata',w/(2*pi),'ydata',20*log10(h));
       
       
    elseif strcmp(Action,'clear')
       set(Hqsynth_(i_ripl),'userdata',[]);
       set(Hqsynth_(i_ripv),'userdata',[]);
       set(Hqsynth_(i_cv),'string','');
       set(Hqsynth_(i_lv),'string','');
       set(Hqsynth_(i_pl2),'xdata',[],'ydata',[]);
       set(Hqsynth_(i_pl1),'xdata',[],'ydata',[]);
       
    else
       disp([Action,' not reconized in qsynth'])
    end;
    

% end qsynth

function [aout,bout,cout,dout,qout]=pabcd(ain,bin,cin,din,qin,element,val1,val2,val3)
% [aout,bout,cout,dout,qout]=pabcd(ain,bin,cin,din,qin,element,val1,val2)
% Uses chain matrix parameters to cascades abcd with denominator q (in) 
% with an element that has val1 (val2 for LC). 
% Useful for computing functions & parameters of ladder networks. 
% element code   description   
%     rs       = series resistor
%     lcs      = shunt series lc val1=l val2=c
%     ls       = series l
%     cp       = shunt c
%     rp       = shunt r
%     lcp      = series chunt lc val1=l val2=c val3 = r (in series with l for loss)
% 
%     a*e2-b*i2 = e1
%     c*e2-d*i2 = i1
% 
% Dick Benson 
%

      if strcmp(element,'rs')
           % rs  = series resistor
           a = 1;
           b = val1;
           c = 0;
           d = 1;
           q = 1;
      elseif strcmp(element,'lcs')
           % lcs = shunt series lc
           % l=val1 c=val2
           q = [val1*val2, 0 , 1];
           a = q;
           b = 0;
           c = [val2 0];
           d = q;
           
      elseif strcmp(element,'lcp')
          % l=val1 c=val2
           q = [val1*val2 val2*val3 1];
           a = q;
           b = [val1 val3];
           c = 0;
           d = q;
      elseif strcmp(element,'ls')     
           % ls = series l
           a = 1;
           b = [val1 0];
           c = 0;
           d = 1;
           q = 1;
      elseif strcmp(element,'cp')
           % cp = shunt c
           q = 1;
           a = 1;
           b = 0;
           c = [val1 0];
           d = 1;
      elseif strcmp(element,'rp')
           % rp = shunt r
           q = 1;
           a = 1;
           b = 0;
           c = 1/val1;
           d = 1;     
      else
         disp([element,' not supported in pabcd '])
      end;

      if isempty(ain)
         aout=a;
         bout=b;
         cout=c;
         dout=d;
         qout=q;
      else
         aout = padd(conv(ain,a),conv(bin,c));
         bout = padd(conv(ain,b),conv(bin,d));
         cout = padd(conv(cin,a),conv(din,c));  
         dout = padd(conv(cin,b),conv(din,d)); 
         qout = conv(qin,q);
      end;


% end function

function pout = padd(p1,p2)
    lp1 = length(p1);
    lp2 = length(p2);
    if lp1==lp2
       pout = p1+p2;
    elseif lp2>lp1 
       pout = p2;
       pout((lp2-lp1+1):lp2)=pout((lp2-lp1+1):lp2)+p1;
    else
       pout = p1;
       pout((lp1-lp2+1):lp1)=pout((lp1-lp2+1):lp1)+p2;
    end;
% end padd

function x=s2n(s)
% function x=s2n(s)
% String to Number convertor,
% input string in s, number returned in x if successful,
% [] returned on failure.
% Dick Benson, DSP Technology

% Far less glorified than MATLAB str2num.m (I don't see why it is so complex)
  if strcmp(s,'error')| strcmp(s,'s') 
    x=[];   % errors return the null 
  else
    x=eval(s,'s2n(''error'')');
  end; 
% end function