{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"chapter 2 Amplitude Modulation-Transmission"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.1 Page no 74"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# given\n",
"c=1.4*10**6 #frequency of carrier wave,Hz\n",
"m1=20 #frequency component,Hz\n",
"m2=10*10**3 #KHz\n",
"\n",
"#calculation \n",
"Ur1=c+m1\n",
"Ur2=c+m2\n",
"Lr1=c-m1\n",
"Lr2=c-m2\n",
"\n",
"#result\n",
"#range of upper sideband(usb)\n",
"print\"upper sideband will include frequencies from \",Ur1,\"Hz\"\n",
"print\"to \",Ur2,\"Hz\"\n",
"#range of lower sideband (lsb)\n",
"print\"lower sideband will include frequencies from \",Lr2,\"Hz\"\n",
"print\"to \",Lr1,\"Hz\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"upper sideband will include frequencies from 1400020.0 Hz\n",
"to 1410000.0 Hz\n",
"lower sideband will include frequencies from 1390000.0 Hz\n",
"to 1399980.0 Hz\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.2 Page no 78"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# given\n",
"b=100.0 #maximum p-p carrier (V)\n",
"a=60.0\n",
"d=125.0\n",
"c=35.0\n",
"x=180\n",
"y=0\n",
"\n",
"#Calculation\n",
"m1=((b-a)/(b+a))*100\n",
"m2=((d-c)/(d+c))*100\n",
"m3=((x-y)/(y+x))*100\n",
"\n",
"#result\n",
"print\"(a) percent(m) = \",m1,\"percent\"\n",
"print\"(b) percent(m) = \",m2,\"percent\"\n",
"print\"(c) percent(m) = \",m3,\"percent\"\n",
"print\"(d) this is a case of overmodulation\"\n",
"print\"(e) this is a distorted AM wave as the increase > decrease in carrier's amplitude\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a) percent(m) = 25.0 percent\n",
"(b) percent(m) = 56.25 percent\n",
"(c) percent(m) = 100 percent\n",
"(d) this is a case of overmodulation\n",
"(e) this is a distorted AM wave as the increase > decrease in carrier's amplitude\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.3 Page no 79"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#given\n",
"c=1*10**3 #carrier output\n",
"\n",
"#calculation\n",
"esb= 1/4.0*(c)\n",
"tsp=(esb*2)\n",
"tp=(tsp+c)\n",
"\n",
"#result\n",
"print\"Total transmitted power =\",tp,\"W\"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Total transmitted power = 1500.0 W\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.4 Page no 81"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# given\n",
"m=0.9 #modulation index\n",
"Pc=500 #carrier Power \n",
"\n",
"#calculation\n",
"x=(m**2)/2.0\n",
"y=(1+x)*Pc\n",
"\n",
"#result\n",
"print\"total transmitted power= \",y,\"W\" #total transmitted powwer\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"total transmitted power= 702.5 W\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.5 Page no 81"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# given\n",
"m=0.95 #modulation index\n",
"Pt= 50*10**3 #total transmitted power\n",
"\n",
"#calculation\n",
"x=(m**2)/2.0\n",
"y=1+x\n",
"z=(Pt/y)\n",
"Pi=Pt-z\n",
"\n",
"#result\n",
"print\"Pc = \",round(z,2),\"W\" #carrier power\n",
"print\"total intelligence power = \",round(Pi,2),\"W\" #intelligence signal\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Pc = 34453.06 W\n",
"total intelligence power = 15546.94 W\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.6 Page no 81"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# given\n",
"Ic=12 #antenna current of AM transmitter when unmodulated\n",
"It=13 #current when modulated\n",
"\n",
"#calculation\n",
"import math\n",
"x=2*((13/12.0)**2-1)\n",
"m=math.sqrt(x)\n",
"a=m*100\n",
"\n",
"#result\n",
"print\"percent(m) = \",round(a,0),\"percent\" \n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"percent(m) = 59.0 percent\n"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.7 Page no 82"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# given\n",
"n=0.7 #efficiency\n",
"c=10*10**3 #carrier wave\n",
"\n",
"#calculation\n",
"Is=0.5*c #intelligence signal\n",
"p=(Is/n)\n",
"\n",
"#result\n",
"print\"dc input power = \",round(p,2),\"W\" #dc input power"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"dc input power = 7142.86 W\n"
]
}
],
"prompt_number": 14
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.8 Page no 82"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#given\n",
"Pc=10.0*10**3 #carrier power\n",
"Pt=11.2*10**3 #transmitted power\n",
"m2=0.5 #modulation index of another sine wave\n",
"\n",
"#calculation\n",
"import math\n",
"x=2*((Pt/Pc)-1)\n",
"m=math.sqrt(x)\n",
"meff=math.sqrt((m**2)+(m2**2))\n",
"a=Pc*(1+((meff**2)/2.0))\n",
"\n",
"#result\n",
"print\"Pt = \",a,\"W\" #total transmitted power"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Pt = 12450.0 W\n"
]
}
],
"prompt_number": 15
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2.9 Page no 100"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# given\n",
"v1=1.0\n",
"v2=0.03\n",
"v3=0.05\n",
"v4=0.02\n",
"v5=0.04\n",
"\n",
"#calculation\n",
"import math\n",
"x=math.sqrt((v2**2+v3**2+v4**2+v5**2)/v1**2)\n",
"y=x*100\n",
"\n",
"#result\n",
"print\"THD = \",round(y,2),\"percent\" #Total harmonic distortion "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"THD = 7.35 percent\n"
]
}
],
"prompt_number": 4
}
],
"metadata": {}
}
]
}