from necpp import *

import math

def handle_nec(result):

if (result != 0):

print(nec_error_message())

def geometry(freq, base, length):

conductivity = 1.45e6 # Stainless steel

ground_conductivity = 0.002

ground_dielectric = 10

wavelength = 3e8/(1e6*freq)

n_seg = int(math.ceil(50*length/wavelength))

nec = nec_create()

'''

\brief Set the prameters of the medium (permittivity and permeability)

\param permittivity The electric permittivity of the medium (in farads per meter)

\param permeability The magnetic permeability of the medium (in henries per meter)

\remark From these parameters a speed of light is chosen.

'''

permittivity = 8.8e-12 # Farads per meter

permeability = 4*math.pi*1e-7

handle_nec(nec_medium_parameters(nec, 2.0*permittivity, permeability))

handle_nec(nec_wire(nec, 1, n_seg, 0, 0, base, 0, 0, base+length, 0.002, 1.0, 1.0))

handle_nec(nec_geometry_complete(nec, 1))

handle_nec(nec_ld_card(nec, 5, 0, 0, 0, conductivity, 0.0, 0.0))

handle_nec(nec_gn_card(nec, 0, 0, ground_dielectric, ground_conductivity, 0, 0, 0, 0))

handle_nec(nec_fr_card(nec, 0, 1, freq, 0))

# Voltage excitation one third of the way along the wire

handle_nec(nec_ex_card(nec, 0, 0, int(n_seg/3), 0, 1.0, 0, 0, 0, 0, 0))

return nec

def impedance(freq, base, length):

nec = geometry(freq, base, length)

handle_nec(nec_xq_card(nec, 0)) # Execute simulation

index = 0

z = complex(nec_impedance_real(nec,index), nec_impedance_imag(nec,index))

nec_delete(nec)

return z

if (__name__ == '__main__'):

z = impedance(freq = 134.5, base = 0.5, length = 4.0)

print("Impedance at base=%0.2f, length=%0.2f : (%6.1f,%+6.1fI) Ohms" % (0.5, 4.0, z.real, z.imag))