Code covered by the BSD License

### Highlights fromUsing S-Parameters in MATLAB & Simulink

from Using S-Parameters in MATLAB & Simulink by Dick Benson
Example of rf amplifier design using S parameters in both MATLAB and Simulink.

zmatch_4(r1_v,r2_v,Q,f)
```function [L1,L2,C1,C2] = zmatch_4(r1_v,r2_v,Q,f)
% [L1 L2 C1 C2 ] = zmatch_4(r1_v,r2_v,Q,f)
% RCA SP-50 03-1967, pp262 (cicuit c)
%
%   ----L1 --------C1---- ------L2-----
%   |                    |            |
%   R1                   C2           R2
%   |                    |            |
%   -----------------------------------
%
%   R1 > R2
%
% Copywrite 2002-2010 The MathWorks, Inc.
syms r1 r2 xl1 xl2 xc1 xc2

if r1_v >  r2_v
% proceed
else
error('In zmatch_4.m', 'r1 should be > r2')
end;

z = r2 + j*xl2;
y = j/xc2 + 1/z;
z = 1/y - j*xc1 + j*xl1;

r2  = r2_v;
r1  = r1_v;
xl1 = Q*r1;
xl2 = (r2/Q)*(sqrt(r1*(Q^2 + 1)/r2) -1);
xc1 = (r1*(Q^2+1)/Q)*(1 - sqrt(r2/(r1*(Q^2+1))));
xc2 = (r1/Q)*sqrt(r2*(Q^2+1)/r1);

w = 2*pi*f;

L1 = xl1/w;
L2 = xl2/w;
C1 = 1/(w*xc1);
C2 = 1/(w*xc2);
```