1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter 15: RADIO WAVE PROPOGATION"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 15.2_1: example_1.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"clc;\n",
"//page no 538\n",
"//prob no. 15.2.1\n",
"// satellite communication system is given \n",
"ht=36000;//height of satellite in km\n",
"f=4000;//freq used in MHz\n",
"Gt=15;//transmitting antenna gain\n",
"Gr=45;//receiving antenna gain\n",
"// A) Determination of free-space transmission loss\n",
"L=32.5+20*log10(ht)+20*log10(f);\n",
"disp('dB',L,'The free-space transmission loss is');\n",
"// B) Determination of received power Pr\n",
"Pt=200;//transmitted power in watt\n",
"Pr_Pt=Gt+Gr-L;//power ration in dB\n",
"Pr_Pt_watt=10^(Pr_Pt/10);//power ratio in watts\n",
"//Therefore\n",
"Pr=Pt*Pr_Pt_watt;\n",
"disp('watts',Pr,'The received power');"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 15.2_2: example_2.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"clc;\n",
"//page no 539\n",
"//prob no. 15.2.2\n",
"// In the given problemhalf dipole antenna is given\n",
"Pr=10;//radiated power in watt\n",
"f=150;//freq used in MHz\n",
"d2=50;//distance of dipole in km\n",
"//we know for the half dipole the maximum gain is 1.64:1,and the effectie length is wl/pi. Therefore open-ckt voltage induced is given as\n",
"Vs=sqrt(30*Pr*1.64)/(d2*10^3)*2/%pi;\n",
"disp('uV',Vs*10^6,'The open-ckt voltage induced is ');"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 15.3_1: example_3.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"clc;\n",
"//page no 545\n",
"//prob no. 15.3.1\n",
"// VHF mobile radio system is given \n",
"Pt=100;//transmitted power\n",
"f=150;//freq used in MHz\n",
"d1=20;//height of transmitting antenna in m\n",
"Gt=1.64;//transmitting antenna gain\n",
"ht=2;//height of receiving antenna in m\n",
"d2=40;// distance in km\n",
"wl=c/(f*10^6);\n",
"E0=sqrt(30*Pt*Gt)\n",
"// Field strength at a receiving antenna is\n",
"ER=(E0*4*%pi*d1*ht)/(wl*(d2*10^3)^2);\n",
"disp('uV/m',ER*10^6,'Field strength at a receiving antenna is');"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 15.3_2: example_4.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"clc;\n",
"//page no 548\n",
"//prob no. 15.3.2\n",
"ht1=100;ht2=60;//antenna heights in ft\n",
"dmax_miles=sqrt(2*ht1)+sqrt(2*ht2);\n",
"disp('miles',dmax_miles,'The maximum range is');"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 15.4_1: example_5.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"clc;\n",
"//page no 560\n",
"//prob no. 15.4.1\n",
"ht=200;//virtual height in km\n",
"a=6370;//in km\n",
"B_degree=20;\n",
"B_rad=20*%pi/180;//angle of elevation in degree\n",
"// The flat-earth approximation gives \n",
"d=2*ht/tand(B_degree);\n",
"disp('km',d,'d=');\n",
"// By using radian measures for all angles\n",
"d=2*a*(((%pi/2)-B_rad)-(asin(a*cosd(B_degree)/(a+ht))));\n",
"disp('km',d,'d=');"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 15.7_1: example_6.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"clc;\n",
"//page no 574\n",
"//prob no. 15.7.1\n",
"// In this problem data regarding the sea water is given\n",
"conductivity = 4;//measured in S/m\n",
"rel_permittivity =80;\n",
"u=4*%pi*10^-7;\n",
"f1=100;//measured in Hz\n",
"f2=10^6;//measured in Hz\n",
"// A) first it is necessary to evaluate the ratio of conductivity/w*rel_permittivity\n",
"w1=2*%pi*f1;\n",
"r=conductivity/w1*rel_permittivity;\n",
"//after the calculation this ratio is much greater than unity. Therefore we have to use following eq to calculate the attenuation coeff as\n",
"a=sqrt(w1*conductivity*u/2);\n",
"disp('N/m',a,'The attenuation coeff is');\n",
"// By using the conversion factor 1N=8.686 dB\n",
"a_dB=a*8.686;\n",
"disp('dB/m',a_dB,'The attenuation coeff in dB/m is');\n",
"// B)\n",
"w2=2*%pi*f2;\n",
"r=conductivity/w2*rel_permittivity;\n",
"//after the calculation this ratio is much greater than unity. Therefore we have to use following eq to calculate the attenuation coeff as\n",
"a=sqrt(w2*conductivity*u/2);\n",
"disp('N/m',a,'The attenuation coeff is');\n",
"// By using the conversion factor 1N=8.686 dB\n",
"a_dB=a*8.686;\n",
"disp('dB/m',a_dB,'The attenuation coeff in dB/m is');"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Scilab",
"language": "scilab",
"name": "scilab"
},
"language_info": {
"file_extension": ".sce",
"help_links": [
{
"text": "MetaKernel Magics",
"url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
}
],
"mimetype": "text/x-octave",
"name": "scilab",
"version": "0.7.1"
}
},
"nbformat": 4,
"nbformat_minor": 0
}
|
