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//Chapter 12: The Cylindrical Antenna and the Moment Method
//Example 12-12.2
clc;
//Variable Initialization
z_load = 2.083 + 1605*%i //Conjugate matched load (ohm)
e0 = 1.0 //Electric field magnitude (unitless)
l = 1/10.0 //Length of dipole (lambda)
ima = 0+1*%i //Imaginary number
z11_exact = 0.4935 - 3454*%i //Exact impedance vector(ohm)
z11_apprx = 0.4944 - 3426*%i //Approximate impedance vector(ohm)
z12_exact = 0.4935 + 1753*%i //Exact impedance vector(ohm)
z12_apprx = 0.4945 + 1576*%i //Approximate impedance vector(ohm)
z13_exact = 0.4935 + 129.9*%i //Exact impedance vector(ohm)
z13_apprx = 0.4885 + 132.2*%i //Approximate impedance vector(ohm)
//Calculation
d = l/4 //Length of each segment (lambda)
vm = (2*e0/(2*%pi))*tan(2*%pi*d/2) //Voltage vector (VA)
z22 = z11_exact + z_load //Impedance matrix for loaded dipole (VA)
zmat_exact =([z11_exact+z13_exact,z12_exact;2*z12_exact,z22])//Z(impedance) matrix (unitless)
vmat = ([vm;vm]) //Voltage matrix (unitless)
[i1]= linsolve(zmat_exact,vmat) //Current matrix (unitless)
i1=i1*-1
i3 = i1(1) //Current vector (unitless)
e_zn = (60*tan(2*%pi*d/2))*ima //Free space electric field (V/m)
e_s = i1(1)*e_zn + i1(2)*e_zn + i3*e_zn //Scattered field (V/m)
sigma = 4*%pi*(abs(e_s)**2)/(abs(e0)**2) //Radar Cross section (lambda**2)
//Result
mprintf("The radar cross section using exact values of Z matrix is %.4f lambda square",sigma(1))
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