GA Fitness Function to fit model simulation to measured

Please can one help with suitable fitness function that can make model simulation fit the measurements after extracting Zcb1, Zcb2 and Zcb3 for this ga code. I tried it several times as shown below no success.

function V = PARAMETEREXTRACT(x) f =[1 2 3 4 5]; L=0.03; Zo = 100; Zcb1= x(1); Zok = (1 + (0.055*(1-1i))/sqrt(f)); Zcbk1 = abs(Zcb1*Zok); u = ((494)+(36/f))*1.0e-9; Vpk = 100/u ; Attk = 1.05*(1.9108*sqrt(f)+0.022*f+0.2/sqrt(f))+4*0.04*sqrt(f); Qk = ((Attk)*(0.01))/(8.68588963807); Bk = (2*pi*f*1.0e6)/(Vpk); Yk =(Qk + 1i*Bk); H = (exp(Yk*L) + exp(-Yk*L))/2; N = (exp(Yk*L) - exp(-Yk*L))/2; D1 = (2*Zcbk1*Zo*H) + ((Zcbk1^2+Zo^2)*N); S111 = ((Zcbk1^2-Zo^2)*N)/D1; S112 = (2*Zcbk1*Zo)/D1; S121 = (2*Zcbk1*Zo)/D1; S122 = ((Zcbk1^2-Zo^2)*N)/D1; T111 = ((S112*S121)-(S111*S122))/S121; T112 = S111/S121; T121 = -(S122/S121); T122 = (1/S121); Zcb2= x(2); Zcbk2 = abs(Zcb2*Zok); D2 = (2*Zcbk2*Zo*H) + ((Zcbk2^2+Zo^2)*N); S211 = ((Zcbk2^2-Zo^2)*N)/D2; S212 = (2*Zcbk2*Zo)/D2; S221 = (2*Zcbk2*Zo)/D2; S222 = ((Zcbk2^2-Zo^2)*N)/D2; T211 = ((S212*S221)-(S211*S222))/S221; T212 = S211/S221; T221 = -(S222/S221); T222 = (1/S221); Zcb3= x(3); Zok = (1 + (0.055*(1-1i))/sqrt(f)); Zcbk3 = abs(Zcb3*Zok); D3 = (2*Zcbk3*Zo*H) + ((Zcbk3^2+Zo^2)*N); S311 = ((Zcbk3^2-Zo^2)*N)/D3; S312 = (2*Zcbk3*Zo)/D3; S321 = (2*Zcbk3*Zo)/D3; S322 = ((Zcbk3^2-Zo^2)*N)/D3; T311 = ((S312*S321)-(S311*S322))/S321; T312 = S311/S321; T321 = -(S322/S321); T322 = (1/S321); % program to cascade the Three T matrix to obtain a single output T T1 = [T111 T112 ; T121 T122]; T2 = [T211 T212 ; T221 T222]; T3 = [T311 T312 ; T321 T322]; T = T1*T2*T3; % Program to convert cascaded T matrix output back to S matrix S11 = T(1,2)/T(2,2); % Model simulation Au = 20*log10(abs(S11)); % measurements Ab=[-35.2 -31.2 -29.5 -28.4 -29 ]; % Fitness function Y = abs(abs(Ab)-abs(Au)); V=Y;