LTPDA_FQ2RI Convert frequency/Q pole/zero representation into real and imaginary conjugate pairs. [G,ri]= ltpda_fq2ri(f0, Q) M Hewitson 26-01-07 $Id: ltpda_fq2ri.m,v 1.4 2007/01/26 14:03:24 hewitson Exp $
0001 function [G,ri]= ltpda_fq2ri(f0, Q) 0002 0003 % LTPDA_FQ2RI Convert frequency/Q pole/zero representation into real 0004 % and imaginary conjugate pairs. 0005 % 0006 % [G,ri]= ltpda_fq2ri(f0, Q) 0007 % 0008 % M Hewitson 26-01-07 0009 % 0010 % $Id: ltpda_fq2ri.m,v 1.4 2007/01/26 14:03:24 hewitson Exp $ 0011 % 0012 0013 if(nargin==0) 0014 disp('usage: [G,ri]= ltpda_fq2ri(f0, Q)') 0015 return 0016 end 0017 0018 % a = Q - 0.5 ; 0019 % re = 2*pi*f0 / sqrt(1+tan(a)^2); 0020 % im = re * tan(a); 0021 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 ri = complex(re,im); 0027 0028 % END