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{
"metadata": {
"name": "",
"signature": "sha256:8165b8e5dad1d709dff36c0fb8461bb25ed06730a63d035a743672c074cb35cf"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter07, Loop Antenna"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example No. 7.10.1, page : 7-16"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import numpy as np\n",
"A=1 #m\u00b2(Area of loop)\n",
"N=400 #no. of turns\n",
"Q=100 #Quality factor\n",
"theta=60 #degree(angle)\n",
"Erms=10 #\u00b5V/m(field strength)\n",
"f=1 #MHz(tuned frequency)\n",
"c=3*10**8 #m/s##Speed of light\n",
"lamda=c/(f*10**6) #m(Wavelength)\n",
"Vr=Q*2*np.pi*A*N*np.cos(theta*np.pi/180)*Erms*10**-6/lamda #V(reciever input voltage)\n",
"print \"Input voltage to the receiver = %0.3f mV \" %(Vr*1000)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Input voltage to the receiver = 4.189 mV \n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example No. 7.10.2, page : 7-17"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import numpy as np\n",
"N=12 #no. of turns\n",
"A=1 #m\u00b2(Area of loop)\n",
"Erms=100 #\u00b5V/m(field strength)\n",
"f=10 #MHz(tuned frequency)\n",
"theta=0 #degree(angle)\n",
"c=3*10**8 #m/s##Speed of light\n",
"lamda=c/(f*10**6) #m(Wavelength)\n",
"Vr=2*np.pi*A*N*np.cos(theta*np.pi/180)*Erms*10**-6/lamda #V(reciever input voltage)\n",
"print \"Voltage induced in loop = %0.2f \u00b5V/m \" %(Vr*10**6) "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Voltage induced in loop = 251.33 \u00b5V/m \n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example No. 7.10.3, page : 7-17"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"N=25 #no. of turns\n",
"Vrms=150 #\u00b5V(emf induced)\n",
"f=500 #kHz(tuned frequency)\n",
"A=0.5**2 #m\u00b2(Area of loop)\n",
"theta=0 #degree(angle)\n",
"c=3*10**8 #m/s##Speed of light\n",
"lamda=c/(f*10**3) #m(Wavelength)\n",
"Erms=lamda/(2*np.pi*A*N*np.cos(theta*np.pi/180))*Vrms*10**-6 #V/m(maximum emf induced)\n",
"print \"Field strength = %0.3f mV/m \"%(Erms*10**3) "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Field strength = 2.292 mV/m \n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example No. 7.10.4, page : 7-17"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"N1=1.0 #no. of turns in primary\n",
"N2=8.0 #no. of turns in secondary\n",
"#a=lamda/25 \n",
"aBYlamda=1.0/25 #(temporary calculation)\n",
"#A=np.pi*a**2\n",
"A_BY_lamda_sqr=np.pi*aBYlamda**2 #(temporary calculation)\n",
"Rr1=31200*(N1*A_BY_lamda_sqr)**2 #\u03a9(Radiation resistance for single turn)\n",
"print \"Radiation resistance for single turn loop = %0.4f \u03a9 \" %(Rr1) \n",
"Rr2=31200*(N2*A_BY_lamda_sqr)**2 #\u03a9(Radiation resistance for 8 turn)\n",
"print \"Radiation resistance for 8 turn loop = %0.2f \u03a9 \" %Rr2 "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Radiation resistance for single turn loop = 0.7883 \u03a9 \n",
"Radiation resistance for 8 turn loop = 50.45 \u03a9 \n"
]
}
],
"prompt_number": 11
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example No. 7.10.5, page : 7-18"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"f=100 #MHz(Operating frequency)\n",
"c=3*10**8 #m/s##Speed of light\n",
"lamda=c/(f*10**6) #m(Wavelength)\n",
"a=lamda/25 #m(radius)\n",
"C=2*np.pi*a #m(Circumference)\n",
"d=2*10**-4*lamda #m(Spacing)\n",
"print \"For single turn : \" \n",
"N=1 #n. of turns\n",
"RL_BY_Rr=3430.0/(C**3*f**(3.5)*N*d) #(temporary calculation)\n",
"K=1/(1+RL_BY_Rr)*100 #%(Radiation efficiency)\n",
"print \"Radiation efficiency of single turn = %0.2f %%\" %K\n",
"print \"For Eight turn : \" \n",
"N=8 #no. of turns\n",
"RL_BY_Rr=3430/(C**3*f**(3.5)*N*d) #(temporary calculation)\n",
"K=1/(1+RL_BY_Rr)*100 #%(Radiation efficiency)\n",
"print \"Radiation efficiency of eight turn = %0.2f %%\" % K"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"For single turn : \n",
"Radiation efficiency of single turn = 42.85 %\n",
"For Eight turn : \n",
"Radiation efficiency of eight turn = 85.71 %\n"
]
}
],
"prompt_number": 14
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example No. 7.10.6, page : 7-19"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from fractions import Fraction\n",
"a=0.5 #m(radius)\n",
"f=0.9 #MHz(OPerating frequency)\n",
"c=3*10**8 #m/s##Speed of light\n",
"lamda=c/(f*10**6) #m(wavelength)\n",
"C=2*np.pi*a #m(Circumference)\n",
"if C/lamda<1/3:\n",
" D=3/2 #Directivity\n",
"elif C/lamda>1/3:\n",
" D=0.682*C/lamda #Directivity\n",
"\n",
"print \"Directivity :\" ,Fraction(D)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Directivity : 3/2\n"
]
}
],
"prompt_number": 18
}
],
"metadata": {}
}
]
}
|
