Convert frequency/Q pole/zero representation into real and imaginary conjugate pairs. Returns [ri conj(ri)] ri= pfq2ri(f0, Q) M Hewitson 02-04-07 $Id: pfq2ri.html,v 1.1 2007/06/08 14:15:09 hewitson Exp $
0001 function ri= pfq2ri(f0, Q) 0002 0003 % Convert frequency/Q pole/zero representation into real 0004 % and imaginary conjugate pairs. Returns [ri conj(ri)] 0005 % 0006 % ri= pfq2ri(f0, Q) 0007 % 0008 % M Hewitson 02-04-07 0009 % 0010 % 0011 % $Id: pfq2ri.html,v 1.1 2007/06/08 14:15:09 hewitson Exp $ 0012 % 0013 0014 if(nargin==0) 0015 disp('usage: ri = fq2ri2(f0, Q)') 0016 return 0017 end 0018 0019 if Q <= 0.5 0020 ri = f0; 0021 else 0022 w0 = 2*pi*f0; 0023 re = -w0/(2*Q); 0024 im = w0*sqrt(4*Q*Q-1)/(2*Q); 0025 G = 1/(w0*w0); 0026 tri = complex(re,im); 0027 ri = [tri conj(tri)]'; 0028 end 0029 0030 % END