9 files changed, 125 insertions, 0 deletions
diff --git a/761/CH20/EX20.1/20_1.sce b/761/CH20/EX20.1/20_1.sce
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index 000000000..6dd73e32d
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+++ b/761/CH20/EX20.1/20_1.sce
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+clc;
+// page no 754
+// prob no 20.1
+// part A)
+d=500;
+//By using the equation for velocity of a satellite
+v=sqrt(4*10^11/(d+6400));
+disp('m/s',v,'A) The velocity of a satellite is');
+// The radius of orbit is 
+r=(6400+d)*10^3//in m
+//The orbital period of satellite is
+T=(2*%pi*r)/v;
+disp('sec',T,'The orbital period of satellite is');
+//part B)
+d=36000;
+//By using the equation for velocity of a satellite
+v=sqrt(4*10^11/(d+6400));
+disp('m/s',v,'B) The velocity of a satellite is');
+//The radius of orbit is 
+r=(6400+d)*10^3//in m
+//The orbital period of satellite is
+T=(2*%pi*r)/v;
+disp('sec',T,'The orbital period of satellite is');
+\ No newline at end of file
diff --git a/761/CH20/EX20.2/20_2.sce b/761/CH20/EX20.2/20_2.sce
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index 000000000..8566a825b
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+++ b/761/CH20/EX20.2/20_2.sce
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+clc;
+// page no 757
+// prob no 20.2
+R=6400;//Radius of earth
+L=45;//earth station lattitude
+H=36000//Height of satellite above the  earth;
+ang=atand((6400*sind(45))/(36000+(6400*(1-cosd(45)))));
+disp(ang);
+\ No newline at end of file
diff --git a/761/CH20/EX20.3/20_3.sce b/761/CH20/EX20.3/20_3.sce
new file mode 100755
index 000000000..0e875787a
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+++ b/761/CH20/EX20.3/20_3.sce
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+clc;
+// page no 758
+// prob no 20.3
+//Determination of lenght of geostationary satellite with angle of elavation=30 degree
+r=64*10^5;//Radius of earth
+h=36*10^6;//height of satellite
+theta=30;//angle of elevation 
+d=sqrt(((r+h)^2)-((r*cosd(theta))^2))-(r*sind(theta));
+disp('km',d/1000,'The length of the path is');
+\ No newline at end of file
diff --git a/761/CH20/EX20.4/20_4.sce b/761/CH20/EX20.4/20_4.sce
new file mode 100755
index 000000000..bec0d7887
--- /dev/null
+++ b/761/CH20/EX20.4/20_4.sce
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+clc;
+// page no 759
+// prob no 20.4
+//A satellite transmitter operates at 4GHz with 7W & antenna gain 40dBi
+//Receiver antenna gain 30dBi & path length is 4*10^7
+Gt_dBi=40;Gr_dBi=30;Pt=7;d=40000;//in km
+f=4000;//in MHz
+Pr_Pt_dB=Gt_dBi+Gr_dBi-(32.44+(20*log10(d))+(20*log10(f)));
+//Signal strength at transmitter 
+Pt_dBm=10*log10(Pt/10^-3);
+Pr_dBm=(Pt_dBm)+(Pr_Pt_dB);
+disp('dBm',Pr_dBm,'The value of signal strength at receiver');
+\ No newline at end of file
diff --git a/761/CH20/EX20.5/20_5.sce b/761/CH20/EX20.5/20_5.sce
new file mode 100755
index 000000000..d3a5deb9f
--- /dev/null
+++ b/761/CH20/EX20.5/20_5.sce
@@ -0,0 +1,16 @@
+clc;
+// page no 760
+// prob no 20.5
+// In the given problem
+G=40;// receiving antenna gain
+T_sky=15;// noise temp
+L=0.4;//loss between antenna and LNA input
+T_eq =40;// noise temperature f LNA
+// Fir-st we have to find G in dB
+G_dB = G-L;
+// For the calculation of T, we have to convert the feedhorn loss into a ratio as follows
+L=10^(0.4/10);
+Ta = ((L-1)*290 + T_sky )/ L;
+// The receiver noise temperature is given wrt the chosen reference point,theefore
+Ratio= G -10*log10(Ta+T_eq);
+disp('dB',Ratio,'The receiver noise temperature is');
+\ No newline at end of file
diff --git a/761/CH20/EX20.6/20_6.sce b/761/CH20/EX20.6/20_6.sce
new file mode 100755
index 000000000..6ae6e41c2
--- /dev/null
+++ b/761/CH20/EX20.6/20_6.sce
@@ -0,0 +1,8 @@
+clc;
+// page no 761
+// prob no 20.6
+NF_dB=1.5;// noise fig of a receiver
+NF=10^(NF_dB/10);
+// Equivalent noise temperature is giveb as
+T_eq=290*(NF-1);
+disp('K',T_eq,'Equivalent noise temperature is');
+\ No newline at end of file
diff --git a/761/CH20/EX20.7/20_7.sce b/761/CH20/EX20.7/20_7.sce
new file mode 100755
index 000000000..242d3ba2a
--- /dev/null
+++ b/761/CH20/EX20.7/20_7.sce
@@ -0,0 +1,23 @@
+clc;
+// page no 761
+// prob no 20.7
+// refer prob no 20.5
+d=38000;//distance of satellite from the Earth surface
+P=50;//transmitter power
+G=30;//antenna gain
+f=12000;//frequency in MHz
+B=10^6;// Bandwidth in MHz
+//from problem no 2.5
+G_T=21;
+L_misc=0;
+k_dBW=-228.6;//Boltzmann's constant in dBW
+// There are no miscellaneous loss
+//The stellite transmitting power in dBW is 
+Pt_dBW = 10*log10(P);
+// The EIPR in dBW 
+EIRP_dBW=Pt_dBW + G;
+//FSL in dB
+FSL_dB= 32.44 + (20*log10(d)) + (20*log10(f));
+// The carrier to noise ratio is
+ratio=EIRP_dBW - FSL_dB - L_misc + G_T - k_dBW - 10*log10(B);
+disp('dB',ratio,'The carrier to noise ratio at the receiver is');
+\ No newline at end of file
diff --git a/761/CH20/EX20.8/20_8.sce b/761/CH20/EX20.8/20_8.sce
new file mode 100755
index 000000000..9083bf0d3
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+++ b/761/CH20/EX20.8/20_8.sce
@@ -0,0 +1,11 @@
+clc;
+// page no 762
+// prob no 20.8
+D=40000;// distance of satellite from the earth station
+v=3*10^8;// velo of light
+d=80000;// distance between two earth stations
+// time delay is given as
+t=d/v;
+// total time delay will be twice that of calculated above
+T=2*t;
+disp('sec',T,'The total time delay is ');
+\ No newline at end of file
diff --git a/761/CH20/EX20.9/20_9.sce b/761/CH20/EX20.9/20_9.sce
new file mode 100755
index 000000000..70c21a12e
--- /dev/null
+++ b/761/CH20/EX20.9/20_9.sce
@@ -0,0 +1,15 @@
+clc;
+// page no 769
+// prob no 20.9
+f_down = 4*10^9;// downlink freq
+D=3;//diameter
+n=0.55;//efficiency
+c=3*10^8;//velo of light
+// The gain of a parabolic antenna is given as G=(n*%pi^2*D^2)/wl^2. Therefore wavelength is given as
+wl=c/f_down
+G=(n*%pi^2*D^2)/wl^2;
+G_dB = 10*log10(G);
+disp('dB',G_dB,'The gain of TVRO is ');
+// The beamwidth is given as
+bw= (70*wl)/D;
+disp('degree',bw,'The beamwidth is');
+\ No newline at end of file