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  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "chapter07:Microwave Measurements"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 7.1, Page number 278"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#calculate VSWR\n",
      "#chapter-7 page 278 example 7.1\n",
      "\n",
      "import math\n",
      "a=4.##Length of Waveguide in cm\n",
      "b=2.5##breadth Waveguide in cm\n",
      "f=10.**10.##Frequency in Hz\n",
      "x=0.1##distance between twice minimum power points in cm\n",
      "c=3.*10.**10.##Velocity of Light in cm/sec\n",
      "\n",
      "#CALCULATION\n",
      "wc=2.*a##Cutoff wavelength in TE10 mode in cms\n",
      "w0=(c/f)##Free space wavelength in cms\n",
      "wg=(w0/math.sqrt(1-(w0/wc)**2.))##Guide wavelength in cms\n",
      "S=(wg/(x*(math.pi)))##Voltage Standing Wave Ratio(VSWR) for double minimum method\n",
      "\n",
      "#OUTPUT\n",
      "print '%s %.1f' %('\\nFor double minimum method, Voltage Standing Wave Ratio(VSWR) is S=',S)#\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "For double minimum method, Voltage Standing Wave Ratio(VSWR) is S= 10.3\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 7.2, Page number 279"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#calculate reflected power and VSWR\n",
      "#chapter-7 page 279 example 7.2\n",
      "import math\n",
      "x=3##O/P incident power from first directional coupler in mW\n",
      "y=0.1##O/P reflected power from second directional coupler in mW\n",
      "\n",
      "#CALCULATION\n",
      "Pi=x*100.##Incident Power in mW\n",
      "Pr=y*100.##Reflected Power in mW\n",
      "p=math.sqrt(Pr/Pi)##Reflection Coefficient\n",
      "S=((1+p)/(1-p))##Voltage Standing Wave Ratio(VSWR)\n",
      "\n",
      "#OUTPUT\n",
      "print '%s %.f %s %s %.2f' %('\\nReflected Power is Pr=',Pr,'mW','\\nVoltage Standing Wave Ratio(VSWR)in the main waveguide is S=',S)#\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "Reflected Power is Pr= 10 mW \n",
        "Voltage Standing Wave Ratio(VSWR)in the main waveguide is S= 1.45\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 7.3, Page number 279"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#calculate VSWR\n",
      "import math\n",
      "\n",
      "#Variable declaration\n",
      "Pr = 0.15*10**-3     #reflected power(W)\n",
      "Pi = 2.5*10**-3      #incident power(W)\n",
      "\n",
      "#Calculations\n",
      "rho = math.sqrt(Pr/Pi)\n",
      "s = (1+rho)/(1-rho)\n",
      "\n",
      "#Results\n",
      "print \"VSWR =\",round(s,2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "VSWR = 1.65\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 7.4, Page number 279"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#calculate reflected power\n",
      "import math\n",
      "\n",
      "#Variable declaration\n",
      "s = 2.                    #VSWR\n",
      "Pi = 4.5*10**-3*1000      #incident power(W)\n",
      "c = 30                    #couplers\n",
      "\n",
      "#Calculations\n",
      "#s = (1+rho)/(1-rho)\n",
      "rho = (s-1)/(s+1)\n",
      "Pr = rho**2*Pi\n",
      "\n",
      "#Results\n",
      "print \"Reflected power =\",Pr,\"W\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Reflected power = 0.5 W\n"
       ]
      }
     ],
     "prompt_number": 4
    }
   ],
   "metadata": {}
  }
 ]
}