{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter 6 : Receivers"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 1 : pg 227"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The Bandwidth at 1700kHz is 17.743 kHz\n"
]
}
],
"source": [
" \n",
"#page no 227\n",
"#prob no. 6.1\n",
"#calculate the bandwidth\n",
"#given\n",
"from math import sqrt\n",
"#A tuned ckt with broadast band (540 to 1700 kHz).Bw=10kHz at 540 kHz\n",
"BW1=10.*10**3;f1=540.*10**3;f2=1700.*10**3;#all in Hz\n",
"#calculations\n",
"#Determination of BW at 1700kHz\n",
"BW2=BW1*sqrt(f2/f1);\n",
"#results\n",
"print 'The Bandwidth at 1700kHz is ',round(BW2/1000,3),'kHz'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 4 : pg 236"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The voltage value of signal is 1.581 mV\n"
]
}
],
"source": [
" \n",
"#page no 236\n",
"#prob no. 6.4\n",
"#calculate the voltage value of the signal\n",
"#given\n",
"#A receiver with sensitivity 0.5uV & blocking dynamic range 70dB.\n",
"#Determination of vpltage signal V1 \n",
"P1_P2=70.;V2=0.5*10**-6;#let\n",
"#calculations\n",
"V1=V2*10**(P1_P2/20);\n",
"#results\n",
"print 'The voltage value of signal is',round(V1*1000,3),'mV'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 5 : pg 238"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"a)The image freq is 1500.0 kHz\n",
"b)The image rejection is 38.687 dB\n"
]
}
],
"source": [
" \n",
"#page no 238\n",
"#prob no. 6.5\n",
"#calculate the image freq and rejection\n",
"#Refer the fig 6.5\n",
"from math import sqrt, log10\n",
"#A receiver tuned to station at 590kHz \n",
"#given\n",
"f_if=455.*10**3;#Intermediate freq\n",
"f_sig=590.*10**3;\n",
"#calculations and results\n",
"#a)Determintion of image freq\n",
"f_image=f_sig+2*f_if;\n",
"print 'a)The image freq is',f_image/1000,'kHz'\n",
"Q=40.;#Q_factor\n",
"#b)Determination of image rejection \n",
"x=(f_image/f_sig)-(f_sig/f_image);\n",
"Asig_Aimage=sqrt(1+(Q*x)**2);#image rejection\n",
"#converting in dB\n",
"IR_dB=20*log10(Asig_Aimage);\n",
"print 'b)The image rejection is',round(IR_dB,3),'dB'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 6 : pg 239"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"All freqs are in MHz. The different freqs are [ 10. -0.9 21.8 0. ] [ 10. -0.9 21.8 0. ]\n"
]
}
],
"source": [
" \n",
"#page no 239\n",
"#prob no. 6.6\n",
"#calculate the frequencies in all cases\n",
"#given\n",
"import numpy\n",
"#An AM high-freq receiver with IF=1.8MHz tuned at freq 10MHz\n",
"f_sig = 10\n",
"f_if = 1.8#All freq in MHz\n",
"#calculations\n",
"#Determination of local oscillator freq f_lo\n",
"f_lo = f_sig + f_if\n",
"#determination of freq. that cause IF response\n",
"m = ([1, 1, 2, 2])#values of m that are integer\n",
"n = ([1, 2, 1, 2])#values of n that are integer\n",
"fs1 = fs2 = numpy.zeros(4);\n",
"for i in range(0,3):\n",
" fs1[i] = ((m[i] / n[i]) * (f_lo)) + ((f_if) / n[i])\n",
"\n",
"for i in range(0,3):\n",
" fs2[i] = ((m[i] / n[i]) * (f_lo)) - ((f_if) / n[i])\n",
"\n",
"print 'All freqs are in MHz.','The different freqs are',fs1,fs2"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7 : pg 245"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"the sensitivity of detector is 60.0 uV/Hz\n"
]
}
],
"source": [
" \n",
"#page no 245\n",
"#prob no. 6.7\n",
"#calculate the sensitivity of detector\n",
"#An FM detector produce Vpp=1.2V with dev=10kHz\n",
"#given\n",
"Vpp=1.2;dev=10.*10**3;\n",
"#calculations\n",
"#Determination of detector sensitivity\n",
"Vp=Vpp/2;#Peak voltage\n",
"kd=Vp/dev;\n",
"#results\n",
"print 'the sensitivity of detector is',kd*10**6,'uV/Hz'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 8 : pg 249"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The RMS voltage is 0.53 V\n"
]
}
],
"source": [
" \n",
"#page no 249\n",
"#prob no. 6.8\n",
"#calculate the rms voltage\n",
"from math import sqrt\n",
"#given\n",
"#A PLL FM detector with kf=100kHz/V & dev=75kHz\n",
"kf=100.*10**3;dev=75.*10**3;\n",
"#calculations\n",
"#Determination of RMS voltage\n",
"Vp_op=dev/kf;\n",
"#Converting peak voltage in RMS voltage\n",
"V_RMS=Vp_op/sqrt(2);\n",
"#results\n",
"print 'The RMS voltage is',round(V_RMS,3),'V'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 9 : pg 258"
]
},
{
"cell_type": "code",
"execution_count": 9,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"a)The critical coupling factor is 0.029\n",
"b)The optimum coupling factor is 0.043\n",
"c)The BW using optimum coupling factor is 19.702 kHz\n"
]
}
],
"source": [
" \n",
"#page no 258\n",
"#prob no. 6.9\n",
"#calculate the critical and optimum coupling factor, BW\n",
"from math import sqrt\n",
"#given\n",
"#An IF transformer at 455kHz & primary ckt has Qp=40 & secondary Q=30\n",
"fo=455.*10**3;Qp=40.;Qs=30.;\n",
"#calculations and results\n",
"#a)Determination of critical coupling factor\n",
"kc=1/sqrt(Qp*Qs);\n",
"print 'a)The critical coupling factor is',round(kc,3)\n",
"#b)Determination of optimum coupling factor\n",
"Kopt=1.5*kc;\n",
"print 'b)The optimum coupling factor is',round(Kopt,3)\n",
"#c)Determination of optimum coupling factor\n",
"B=Kopt*fo;\n",
"print 'c)The BW using optimum coupling factor is',round(B/1000,3),'kHz'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 10 : pg 261"
]
},
{
"cell_type": "code",
"execution_count": 10,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The first IF is 4.5 MHz\n",
"The second IF is 500.0 kHz\n"
]
}
],
"source": [
" \n",
"#page no 261\n",
"#prob no. 6.10\n",
"#calculate the first and second IF\n",
"#given\n",
"#Receiver refering in fig.6.28\n",
"f_sig=25*10**6;#signal i/p freq\n",
"f_lo1=29.5*10**6;#Ist local oscillator freq\n",
"#calculations and results\n",
"#determination of Ist IF which uses high side injection\n",
"f_IF1=f_lo1-f_sig;#high side injection\n",
"print 'The first IF is',f_IF1/10**6,'MHz'\n",
"#Determination of IInd IF which uses low side injection\n",
"f_lo2=4*10**6;#IInd local oscillator freq\n",
"f_IF2=f_IF1-f_lo2;\n",
"print 'The second IF is',f_IF2/10**3,'kHz'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 11 : pg 265"
]
},
{
"cell_type": "code",
"execution_count": 11,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Signal strength at receiver i/p is 6.295 uV\n"
]
}
],
"source": [
" \n",
"#page no 265\n",
"#prob no. 6.11\n",
"#calculate the signal strength at receiver i/p\n",
"#An S-meter is given\n",
"#given\n",
"V1=50*10**-6;#signal strength at transmitter in V\n",
"P=18.;#18 dB power\n",
"#calculations\n",
"V2=V1/(10**(P/20.));\n",
"#results\n",
"print 'Signal strength at receiver i/p is' ,round(V2*10**6,3),'uV'"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 2",
"language": "python",
"name": "python2"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 2
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython2",
"version": "2.7.11"
}
},
"nbformat": 4,
"nbformat_minor": 0
}