initial commit / add all books

19 files changed, 536 insertions, 0 deletions

diff --git a/135/CH11/EX11.1/EX1.sce b/135/CH11/EX11.1/EX1.sce
new file mode 100755
index 000000000..8c8d8ab6e
--- /dev/null
+++ b/135/CH11/EX11.1/EX1.sce
@@ -0,0 +1,14 @@
+// Example 11.1: Open-loop gain, Return ratio, Reverse transmission β of feedback circuit

+clc, clear

+// Let A be open-loop gain and B be return ratio

+// For A, B 10% higher, -1.1A + 55.11B = -50.1

+// For A, B 10% lower, -0.9A + 44.91B = -49.9

+// Solving the two equations

+a=[-1.1 55.11; -0.9 44.91];

+b=[-50.1; -49.9];

+c=inv(a)*b;

+A=c(1,1);

+B=c(2,1);

+disp(A,"Open-loop gain =");

+disp(B,"Return ratio =");

+disp(B/A,"Reverse transmission β of the feedback circuit =");
\ No newline at end of file
diff --git a/135/CH11/EX11.11/EX11.sce b/135/CH11/EX11.11/EX11.sce
new file mode 100755
index 000000000..4f2ba041a
--- /dev/null
+++ b/135/CH11/EX11.11/EX11.sce
@@ -0,0 +1,18 @@
+// Example 11.11: (a) Amplifier type

+//                (b) Input resistance, Output resistance, Transfer ratio

+clc, clear

+r_pi=1e3; // in ohms

+gm=0.1; // in mho

+

+disp("Part (a)");

+disp("It ia a CB-CE cascade, configuration. It has low input and high output impedance and hence corresponds to a current     amplifier.");

+

+disp("Part (b)");

+// From low frequency equivalent circuit in Fig. 11.40

+btao=gm*r_pi;

+Rin=r_pi/(1+btao); // Input resistance in ohms

+Rout=%inf; // Output resistance (= ro of Q2)

+Ai=gm*gm*Rin*3e3*1e3/(3e3+1e3); // Transfer ratio

+disp(Rin,"Input resistance (Ω​) =");

+disp(Rout,"Output resistance =");

+disp(Ai,"Transfer ratio =");
\ No newline at end of file
diff --git a/135/CH11/EX11.12/EX12.sce b/135/CH11/EX11.12/EX12.sce
new file mode 100755
index 000000000..5c18a0dce
--- /dev/null
+++ b/135/CH11/EX11.12/EX12.sce
@@ -0,0 +1,14 @@
+// Example 11.12: (b) AF

+clc, clear

+AV=4000;

+bta=1/300;

+RS=2; // in kilo-ohms

+RE=RS; // in kilo-ohms

+RC=6; // in kilo-ohms

+btao=200;

+r_pi=4; // in kilo-ohms

+

+disp("Part (b)");

+x=-AV*-btao*RC/(r_pi+RS);

+AF=x/(1+x*bta);

+disp(AF,"AF =");
\ No newline at end of file
diff --git a/135/CH11/EX11.13/EX13.sce b/135/CH11/EX11.13/EX13.sce
new file mode 100755
index 000000000..84675de96
--- /dev/null
+++ b/135/CH11/EX11.13/EX13.sce
@@ -0,0 +1,30 @@
+// Example 11.13: (a) Amplifier type

+//                (b) Input resistance, Output resistance, Transfer ratio

+clc, clear

+r_pi=1e3; // in ohms

+gm=0.1; // in mho

+

+disp("Part (a)");

+disp("Q1 is a common collector and Q2 is common emitter stage. Hence the given circuit is cascade of cc and CE stages. As the Rin of a CC is high and the Ro of the CE is low, therefore, the given circuit approximates a voltage amplifier. If RL is chosen a low resistance, the amplifier can be considered a voltage-to-current converter.")

+

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+

+disp("Part (b)");

+// From the Fig. 11.42

+RE1=3e3; // in ohms

+RC2=0.6e3; // in ohms

+btao=gm*r_pi;

+Ri2=r_pi; // in ohms

+Ri1=r_pi+(1+btao)*parallel(RE1,Ri2); // Input resistance in ohms

+Rout=RC2; // Output resistance (= ro of Q2)

+AV1=(1+btao)*RE1/(r_pi+(1+btao)*RE1);

+Ro1=parallel(RE1,r_pi/(1+btao)); // in ohms

+AV2=-btao*RC2/(Ro1+r_pi);

+AV=AV1*AV2;

+Ri1=Ri1*1e-3; // in kilo-ohms

+Rout=Rout*1e-3; // in kilo-ohms

+disp(Ri1,"Input resistance (Ω​) =");

+disp(Rout,"Output resistance =");

+disp(AV,"Transfer ratio =");
\ No newline at end of file
diff --git a/135/CH11/EX11.15/EX15.sce b/135/CH11/EX11.15/EX15.sce
new file mode 100755
index 000000000..cb7faefc1
--- /dev/null
+++ b/135/CH11/EX11.15/EX15.sce
@@ -0,0 +1,34 @@
+// Example 11.15: Small signal gain, Input resistance, Output resistance

+clc, clear

+btao=100;

+r_pi=1e3; // in ohms

+ICQ=2.5e-3; // in amperes

+VT=25e-3; // in volts

+gm=ICQ/VT; // Transconductance in mho

+r_pi=btao/gm; // Incremental resistance of emitter-base diode in ohms

+// From ac model without feedback in Fig. 11.47

+RS=10e3; // in ohms

+RF=47e3; // in ohms

+RC=4.7e3; // in ohms

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+AoL=-gm*parallel(RF,RC)*parallel(RS,parallel(RF,r_pi)); // in ohms

+bta=1/RF;

+T=-bta*AoL;  // Return ratio

+AF=AoL/(1+T); // in ohms

+AVF=AF/RS; // Small signal gain

+RID=parallel(RF,r_pi); // in ohms

+RID_dash=parallel(RID,RS); // in ohms

+RIF_dash_I=RID_dash/(1+T); // in ohms

+RIF_I=RS*RIF_dash_I/(RS-RIF_dash_I); // in ohms

+RIF_dash_V=RS+RIF_I; // in ohms

+RoD_dash=parallel(RF,RC); // in ohms

+RoF_dash=RoD_dash/(1+T); // in ohms

+RoF=RoF_dash*RC/(RC-RoF_dash); // in ohms

+disp(RoF);

+RIF_dash_V=RIF_dash_V*1e-3; // in kilo-ohms

+RoF=RoF*1e-3; // in kilo-ohms

+disp(AVF,"Small signal gain =");

+disp(RIF_dash_V,"Input resistance (kΩ​) =");

+disp(RoF,"Output resistance (kΩ​) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.16/EX16.sce b/135/CH11/EX11.16/EX16.sce
new file mode 100755
index 000000000..3254d96ab
--- /dev/null
+++ b/135/CH11/EX11.16/EX16.sce
@@ -0,0 +1,42 @@
+// Example 11.16: (a) AF, T

+//                (b) R1F, RoF

+clc, clear

+btao=150;

+ICQ=1.5e-3; // in amperes

+VT=25e-3; // Voltage equivalent to temperatue at room temperature in volts

+// From circuit without feedback but with loading in Fig. 11.50

+RS=2e3; // in ohms

+RE1=0.1e3; // in ohms

+RF=6.2e3; // in ohms

+RC1=4.3e3; // in ohms

+RC2=1.2e3; // in ohms

+RL=4.7e3; // in ohms

+

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+

+disp("Part (a)");

+gm=ICQ/VT; // Transconductance in mho

+r_pi=btao/gm; // Incremental resistance of emitter-base diode in ohms

+AV1=-btao*RC1/(RS+r_pi+(1+btao)*parallel(RE1,RF));

+AV2=-btao*parallel(RC2,parallel(RF+RE1,RL))/(RC1+r_pi);

+AoL=AV1*AV2;

+bta=-RE1/(RE1+RF);

+T=-bta*AoL;

+AF=AoL/(1+T);

+disp(AF,"AF =");

+disp(T,"T =");

+

+disp("Part (b)");

+RID=r_pi+(1+btao)*parallel(RE1,RF); // in ohms

+RID_dash=RS+RID; // in ohms

+RIF_dash=RID_dash*(1+T); // in ohms

+RIF=RIF_dash-RS; // in ohms

+RoD=parallel(RC2,RF+RE1); // in ohms

+RoD_dash=parallel(RoD,RL); // in ohms

+RoF_dash=RoD_dash/(1+T); // in ohms

+RoF=RL*RoF_dash/(RL-RoF_dash); // in ohms

+RIF=RIF*1e-3; // in kilo-ohms

+disp(RIF,"RIF (kΩ​) =");

+disp(RoF,"RoF (Ω​) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.17/EX17.sce b/135/CH11/EX11.17/EX17.sce
new file mode 100755
index 000000000..50bdac449
--- /dev/null
+++ b/135/CH11/EX11.17/EX17.sce
@@ -0,0 +1,37 @@
+// Example 11.17: (a) T, AoL, AF

+//                (b) RoF

+clc, clear

+gm=1e-3; // in mho

+rd=20e3; // in ohms

+

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+

+disp("Part (a)");

+// From the ac equivalent circuit in Fig. 11.52

+RF=10e3; // in ohms

+RD1=10e3; // in ohms

+RL=10e3; // in ohms

+ro=20e3; // in ohms

+RS=parallel(0.47e3,RF); // in ohms

+RL2=parallel(ro,parallel(10.47e3,RL)); // in ohms

+mu=rd*gm; // Amplification factor

+AV1=-mu*RD1/(RD1+rd+(1+mu)*RS);

+AV2=-gm*RL2;

+AoL=AV1*AV2;

+bta=-0.47/(10+0.47); // Feedback factor

+T=-bta*AoL;

+AF=AoL/(1+T);

+disp(T,"T =");

+disp(AoL,"AoL =");

+disp(AF,"AF =");

+

+disp("Part (b)");

+RoD=parallel(ro,10.47e3); // in ohms

+TSC=0; // for RL=0, T=0

+ToC=bta*AV1*gm*RoD;

+// By Blackman's relation

+RoF=RoD*(1+TSC)/(1+ToC); // in ohms

+RoF=RoF*1e-3; // in kilo-ohms

+disp(RoF,"RoF (kΩ) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.18/EX18.sce b/135/CH11/EX11.18/EX18.sce
new file mode 100755
index 000000000..db4da278a
--- /dev/null
+++ b/135/CH11/EX11.18/EX18.sce
@@ -0,0 +1,29 @@
+// Example 11.18: T, AoL, AF

+clc, clear

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+ICQ1=0.25e-3; // in amperes

+ICQ2=-0.5e-3; // in amperes

+bta1=200;

+VA1=125; // in volts

+bta2=150;

+VT=25e-3; // Voltage equivalent to temperatue at room temperature in volts

+gm1=ICQ1/VT; // in mho

+gm2=abs(ICQ2)/VT; // in mho

+r_pi1=bta1/gm1; // in ohms

+r_pi2=bta2/gm2; // in ohms

+ro1=VA1/ICQ1; // in ohms

+// From ac equivalent circuit in Fig. 11.56

+RC1=20e3; // in ohms

+RS=1e3; // in ohms

+bta=-0.82/(20+0.82); // Feedback factor

+RL1=parallel(RC1,ro1); // in ohms

+Ib2_IC1=RL1/(RL1+r_pi2+(1+bta2)*parallel(20e3,0.82e3)); // Ib2/IC1

+Ib1_IS=parallel(RS,20.82e3)/(r_pi1+parallel(RS,20.82e3)); // Ib1/IS

+AoL=bta2*Ib2_IC1*bta1*Ib1_IS; // Current gain without feedback

+T=-bta*AoL;

+AF=AoL/(1+T);

+disp(T,"T =");

+disp(AoL,"AoL =");

+disp(AF,"AF =");
\ No newline at end of file
diff --git a/135/CH11/EX11.19/EX19.sce b/135/CH11/EX11.19/EX19.sce
new file mode 100755
index 000000000..fbba32acc
--- /dev/null
+++ b/135/CH11/EX11.19/EX19.sce
@@ -0,0 +1,46 @@
+// Example 11.19: (a) AIF

+//                (b) R1F

+//                (c) A1F'

+//                (d) AVF

+clc, clear

+btao=50;

+r_pi=2e3; // in ohms

+// From equivalent circuit without feedback but taking loading effect in Fig. 11.58

+RS=1e3; // in ohms

+Rf=15e3; // in ohms

+RE2=10e3; // in ohms

+RC1=10e3; // in ohms

+RC2=10e3; // in ohms

+

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+

+disp("Part (a)");

+RS_dash=parallel(RS,Rf+RE2); // in ohms

+gm=btao/r_pi; // in mho

+RE2_dash=parallel(RE2,Rf); // in ohms

+Rx=r_pi+(1+btao)*RE2_dash; // in ohms

+I2_IS=-gm*parallel(RS_dash,r_pi)*RC1/(RC1+Rx); // I2/IS

+AI=-btao*I2_IS; // Open loop

+If_IS=(1+btao)*I2_IS*RE2/(RE2+Rf); // If/IS

+bta=If_IS/AI; // Feedback factor

+T=-bta*AI;

+AIF=AI/(1+T);

+disp(AIF,"AIF =");

+

+disp("Part (b)");

+RID=parallel(RS,parallel(Rf+RE2,r_pi));

+R1F=RID/(1+T); // in ohms

+disp(R1F,"R1F (Ω) =");

+

+disp("Part (c)");

+Ii_IS=RS/(RS+parallel(Rf+RE2,r_pi)); // Ii'/IS

+AI_dash=AI*Ii_IS;

+T=-bta*AI_dash;

+A1F_dash=AI_dash/(1+T);

+disp(A1F_dash,"A1F =");

+

+disp("Part (d)");

+AVF=AIF*RC2/RS;

+disp(AVF,"AVF =");
\ No newline at end of file
diff --git a/135/CH11/EX11.2/EX2.sce b/135/CH11/EX11.2/EX2.sce
new file mode 100755
index 000000000..84a8471f5
--- /dev/null
+++ b/135/CH11/EX11.2/EX2.sce
@@ -0,0 +1,15 @@
+// Example 11.2: Necessary amount of feedback, Gain without feedback

+clc, clear

+// Let A be gain without feedback and b be necessary amount of feedback

+// AOL can assume values A, 1.1A, 0.9A, i.e. 10% variation

+// For AOL = 1.1A yields, 50.01 + 1.1A(50.01b -1) = 0

+// When AOL = 0.9A, 49.99 + 0.9A(49.99b - 1) = 0 

+// Solving the two equations

+a=[1.1*50.01 -1.1; 0.9*44.99 -0.9];

+b=[-50.01; -49.99];

+c=inv(a)*b;

+d=c(1,1); // A*b

+A=c(2,1);

+b=d/A;

+disp(b,"Necessary amount of feedback =");

+disp(A,"Gain without feedback =");
\ No newline at end of file
diff --git a/135/CH11/EX11.20/EX20.sce b/135/CH11/EX11.20/EX20.sce
new file mode 100755
index 000000000..cff8e6ca2
--- /dev/null
+++ b/135/CH11/EX11.20/EX20.sce
@@ -0,0 +1,45 @@
+// Example 11.20: (a) AVF

+//                (b) AIF

+//                (c) RIF

+//                (d) ROF

+clc, clear

+btao=50;

+r_pi=1.1e3; // in ohms

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+// From equivalent circuit of amplifier without feedback in Fig. 11.60

+RS=4.7e3; // in ohms

+RF=15e3; // in ohms

+RE2=0.1e3; // in ohms

+RB1=parallel(91e3,10e3); // in ohms

+RC1=4.7e3; // in ohms

+RC2=4.7e3; // in ohms

+RB2=RB1; // in ohms

+

+disp("Part (b)");

+RL1=parallel(RS,parallel(RF+RE2,RB1)); // in ohms

+I1_IS=RL1/(RL1+r_pi); // I1/IS

+IC1_IS=btao*I1_IS; // IC1/IS

+Ri2=r_pi+(1+btao)*parallel(RE2,RF); // in ohms

+I2_IS=-IC1_IS*parallel(RC1,RB2)/(parallel(RC1,RB2)+Ri2); // in ohms

+IC2_IS=btao*I2_IS; // IC2/IS

+AID=-IC2_IS/2; // Open loop

+IF_IS=IC2_IS*RE2/(RE2+RF); // IF/IS

+bta=IF_IS/AID; // Feedback factor

+T=-bta*AID;

+AIF=AID/(1+T);

+disp(AIF,"AIF =");

+

+disp("Part (a)");

+AVF=AIF*RC2/RS;

+disp(AVF,"AVF =");

+

+disp("Part (c)");

+RID=parallel(parallel(RS,RE2+RF),parallel(RB1,r_pi)); // in ohms

+RIF=RID/(1+T); // in ohms

+disp(RIF,"RIF (Ω) =");

+

+disp("Part (d)");

+ROF=RC2*1e-3; // in kilo-ohms

+disp(ROF,"ROF (kΩ​) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.21/EX21.sce b/135/CH11/EX11.21/EX21.sce
new file mode 100755
index 000000000..d168d82a8
--- /dev/null
+++ b/135/CH11/EX11.21/EX21.sce
@@ -0,0 +1,52 @@
+// Example 11.21: (c) AF, T

+//                (d) Voltage gain

+clc, clear

+ICQ1=0.25e-3; // in amperes

+ICQ2=1e-3; // in amperes

+ICQ3=0.5e-3; // in amperes

+RC1=5e3; // in ohms

+RC2=7.5e3; // in ohms

+RC3=10e3; // in ohms

+R1=0.2e3; // in ohms

+R2=0.33e3; // in ohms

+RS=0.6e3; // in ohms

+RF=20e3; // in ohms

+btao=200;

+VA=125; // in volts

+VT=25e-3; // Voltage equivalent to temperatue at room temperature in volts

+

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+

+disp("Part (c)");

+gm1=ICQ1/VT; // in mho

+r_pi1=btao/gm1; // in ohms

+ro1=VA/ICQ1; // in ohms

+gm2=ICQ2/VT; // in mho

+r_pi2=btao/gm2; // in ohms

+ro2=VA/ICQ2; // in ohms

+gm3=ICQ3/VT; // in mho

+r_pi3=btao/gm3; // in ohms

+ro3=VA/ICQ3; // in ohms

+Rin1=r_pi1+(btao+1)*parallel(RF+R2,R1); // in ohms

+RL1=parallel(RC1,ro1); // in ohms

+RL2=parallel(RC2,ro2); // in ohms

+Rin2=r_pi2; // in ohms

+Rin3=r_pi3+(btao+1)*parallel(R2,RF+R1); // in ohms

+Io_Ib3=btao; // Io/Ib3

+Ib3_Ic2=-RL2/(RL2+Rin3); // Ib3/Ic2

+Ic2_Ib2=btao; // Ic2/Ib2

+Ib2_Ic1=-RL1/(RL1+Rin2); // Ib2/Ic1

+Ic1_Ib1=btao; // Ic1/Ib1

+Ib1_VS=1/(RS+Rin1); // Ib1/VS in mho

+AoL=Io_Ib3*Ib3_Ic2*Ic2_Ib2*Ib2_Ic1*Ic1_Ib1*Ib1_VS; // Open loop

+bta=-R1*R2/(R1+R2+RF); // Feedback factor

+T=-bta*AoL;

+AF=AoL/(1+T);

+disp(T,"T =");

+disp(AF,"AF =");

+

+disp("Part (d)");

+Vo_VS=-AF*parallel(RC3,ro3);

+disp(Vo_VS,"Voltage gain =");
\ No newline at end of file
diff --git a/135/CH11/EX11.22/EX22.sce b/135/CH11/EX11.22/EX22.sce
new file mode 100755
index 000000000..11f081f72
--- /dev/null
+++ b/135/CH11/EX11.22/EX22.sce
@@ -0,0 +1,27 @@
+// Example 11.22: AF, RoF

+clc, clear

+gm=2e-3; // in mho

+rd=20e3; // in ohms

+RD=12e3; // in ohms

+RG=500e3; // in ohms

+Rs=50; // in ohms

+RF=5e3; // in ohms

+function[c]=parallel(a,b)

+    c=a*b/(a+b);

+endfunction

+Ro=parallel(RD,rd); // in ohms

+AV1=-gm*parallel(RD,parallel(rd,RG));

+AV2=AV1;

+AV3=-gm*parallel(RD,rd);

+AV=AV1*AV2*AV3;

+RG_dash=parallel(RG,RF); // in ohms

+Vi_Vs=RG_dash/(RG_dash+Rs); // Vi/Vs

+AoL=AV*Vi_Vs*RF/(RF+Ro); // Vo/Vs (Open loop)

+bta=1/RF; // Feedback factor

+RM=AoL*Rs; // in ohms

+T=-bta*RM; // Return ratio

+AF=AoL/(1+T);

+RoD=parallel(Ro,RF); // in ohms

+RoF=RoD/(1+T); // in ohms

+disp(AF,"AF =");

+disp(RoF,"RoF (Ω) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.3/EX3.sce b/135/CH11/EX11.3/EX3.sce
new file mode 100755
index 000000000..608925ada
--- /dev/null
+++ b/135/CH11/EX11.3/EX3.sce
@@ -0,0 +1,22 @@
+// Example 11.3: (a) Output voltage

+//               (b) Input voltage

+clc, clear

+B1=36; // Fundamental output in volts

+B2=7*B1/100; // Second-harmonic distortion in volts

+Vs=0.028; // Input in volts

+A=B1/Vs; // Gain

+

+disp("Part (a)");

+b=1.2/100; // Amount of feedback in volts

+B1f=B1/(1+b*A); // Fundamental output with feedback in volts

+B2f=B2/(1+b*A); // Second-harmonic distortion with feedback in volts

+disp(B1f,"Fundamental output with feedback (V) =");

+disp(B2f,"Second-harmonic distortion with feedback (V) =");

+

+disp("Part (b)");

+B1f=36; // Fundamental output with feedback in volts

+B2f=1*B1f/100; // Second-harmonic distortion with feedback in volts

+T=B2/B2f-1; // Return ratio

+AF=A/(1+T); // Feedback gain

+Vs=B1f/AF; // Input voltage in volts

+disp(Vs,"Input voltage (V) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.4/EX4.sce b/135/CH11/EX11.4/EX4.sce
new file mode 100755
index 000000000..f195ad654
--- /dev/null
+++ b/135/CH11/EX11.4/EX4.sce
@@ -0,0 +1,21 @@
+// Example 11.4: Closed loop parameters

+clc, clear

+Av=1000;

+bta=0.01;

+Zin=1; // in kilo-ohms

+Zo=420; // in ohms

+fL=1.5; // in kilo-hertz

+fH=501.5; // in kilo-hertz

+disp("Closed loop parameters :");

+T=Av*bta; // Return ratio

+// From Fig. 11.18

+Af=Av/(1+T); // Closed loop gain

+Zif=Zin*(1+T); // Closed loop input impedance in kilo-ohms

+Zof=Zo/(1+T); // Closed loop output impedance in ohms

+fLf=fL/(1+T); // Closed loop lower 3 dB frequency in kilo-hertz

+fHf=fH*(1+T); // Closed loop upper 3 dB frequency in kilo-hertz

+disp(Af,"Gain =");

+disp(Zif,"Input impedance (kΩ) =");

+disp(Zof,"Output impedance (Ω) =");

+disp(fLf,"Lower 3 dB frequency (kHz) =");

+disp(fHf,"Upper 3 dB frequency (kHz) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.5/EX5.sce b/135/CH11/EX11.5/EX5.sce
new file mode 100755
index 000000000..248a7e03e
--- /dev/null
+++ b/135/CH11/EX11.5/EX5.sce
@@ -0,0 +1,15 @@
+// Example 11.5: Output signal voltage, Output noise voltage, Improvement in S/N ratio

+clc, clear

+A1=1;

+Vs=1; // in volts

+Vn=1; // in volts

+A2=100;

+bta=1;

+Vos=Vs*A1*A2/(1+bta*A1*A2); // Output signal voltage in volts

+Von=Vn*A1/(1+bta*A1*A2); // Output noise voltage in volts

+SNRi=20*log10(Vs/Vn); // Input S/N ratio in dB

+SNRo=20*log10(Vos/Von); // Output S/N ratio in dB

+SNR=SNRo-SNRi; // Improvement in S/N raio in dB

+disp(Vos,"Output signal voltage (V) =");

+disp(Von,"Output noise voltage (V) =");

+disp(SNR,"Improvement in S/N ratio (dB) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.6/EX6.sce b/135/CH11/EX11.6/EX6.sce
new file mode 100755
index 000000000..201cf03e9
--- /dev/null
+++ b/135/CH11/EX11.6/EX6.sce
@@ -0,0 +1,31 @@
+// Example 11.6: (b) R2/R1

+//               (c) Amount of feedback in decibels

+//               (d) Vo, Vf, Vi

+//               (e) Decrease in Af

+clc, clear

+

+disp("Part (b)");

+A=1e4;

+Af=10;

+bta=(A/Af-1)/A; // Feedback factor

+R2_R1=1/bta-1; // R2/R1

+disp(R2_R1,"R2/R1 =");

+

+disp("Part (c)");

+dB=20*log10(1+A*bta); // Amount of feedback in decibels

+disp(dB,"Amount of feedback (dB) =");

+

+disp("Part (d)");

+Vs=1; // in volts

+Vo=Af*Vs; // in volts

+Vf=bta*Vo; // in volts

+Vi=Vs-Vf; // in volts

+disp(Vo,"Vo (V) =");

+disp(Vf,"Vf (V) =");

+disp(Vi,"Vi (V) =");

+

+disp("Part (e)");

+A=80*A/100; // Decreased A

+Af_dash=A/(1+A*bta); // Decreased Af

+C=(Af-Af_dash)*100/Af; // Percentage decrease in Af

+disp(C,"Percentage decrease in Af (%) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.7/EX7.sce b/135/CH11/EX11.7/EX7.sce
new file mode 100755
index 000000000..bf3522d28
--- /dev/null
+++ b/135/CH11/EX11.7/EX7.sce
@@ -0,0 +1,15 @@
+// Example 11.7: Low frequency gain, Upper 3 dB frequency

+clc, clear

+// Without feedback

+AM=1e4; // Low frequency values of A

+wH=100; // Upper 3 dB frequency in hertz

+// With feedback

+R1=1; // in kilo-ohms

+R2=9; // in kilo-ohms

+bta=R1/(R1+R2); // Feedback factor

+AfM=AM/(1+bta*AM); // Low frequency gain

+wHf=wH*(1+bta*AM); // Upper 3 dB frequency in hertz

+wHf=wHf*1e-3; // Upper 3 dB frequency in kilo-hertz

+disp("For closed loop amplifier :");

+disp(AfM,"Low frequency gain =");

+disp(wHf,"Upper 3 dB frequency (kHz) =");
\ No newline at end of file
diff --git a/135/CH11/EX11.9/EX9.sce b/135/CH11/EX11.9/EX9.sce
new file mode 100755
index 000000000..6886b23aa
--- /dev/null
+++ b/135/CH11/EX11.9/EX9.sce
@@ -0,0 +1,29 @@
+// Example 11.9: (a) RE

+//               (b) RL

+//               (c) R1F

+//               (d) Quiescent collector current

+clc, clear

+GmF=1; // Transconductance gain in mili-amperes per volts

+AVF=-4; // Voltage gain

+D=50; // Desensitivity factor

+RS=1; // in kilo-ohms

+btao=150;

+AoL=GmF*D; // Open loop mutual conductance in mili-amperes per volts

+

+disp("Part (a)");

+RE=(D-1)/AoL; // in kilo-ohms

+disp(RE,"RE (kΩ​) =");

+

+disp("Part (b)");

+RL=-AVF/GmF; // in kilo-ohms

+disp(RL,"RL (kΩ​) =");

+

+disp("Part (c)");

+r_pi=btao/AoL-RS-RE; // in kilo-ohms

+R1F=RS+r_pi+(1+btao)*RE; // in kilo-ohms

+disp(R1F,"R1F (kΩ​) =");

+

+disp("Part (d)");

+VT=26e-3; // Voltage equivalent to temperatue at room temperature in volts

+IC=btao*VT/r_pi; // in mili-amperes

+disp(IC,"IC (mA) =");
\ No newline at end of file