4 files changed, 74 insertions, 0 deletions
diff --git a/3773/CH8/EX8.1/Ex8_1.sce b/3773/CH8/EX8.1/Ex8_1.sce
new file mode 100644
index 000000000..7404e7d38
--- /dev/null
+++ b/3773/CH8/EX8.1/Ex8_1.sce
@@ -0,0 +1,14 @@
+//Chapter 8: Helical Antennas
+//Example 8-5.1
+clc;
+
+//Variable Initialization
+w = 5       //Width of flattened tubing at termination (mm)
+Er = 2.7    //Relative permittivity of the sheet
+Z0 = 50     //Characteristic impedance of the sheet
+
+//Calculation
+h = w/((377/(sqrt(Er)*Z0))-2)
+
+//Result
+mprintf("The required thickness of the polystyrene sheet is %.1f mm",h)
diff --git a/3773/CH8/EX8.2/Ex8_2.sce b/3773/CH8/EX8.2/Ex8_2.sce
new file mode 100644
index 000000000..e56ba6995
--- /dev/null
+++ b/3773/CH8/EX8.2/Ex8_2.sce
@@ -0,0 +1,18 @@
+//Chapter 8: Helical Antennas
+//Example 8-5.2
+clc;
+
+//Variable Initialization
+n = 16.0        //Number of turns (unitless)
+C = 1       //Circumference (lambda)
+S = 0.25        //Turn Spacing (lambda)
+
+//Calculation
+hpbw = 52/(C*sqrt(n*S)) //Half power beamwidth (degrees)
+ax_rat = (2*n + 1)/(2*n)    //Axial ratio (unitless)
+gain = 12*(C**2)*n*S        //Gain of antenna (unitless)
+gain_db = 10*log10(gain)    //Gain of antenna (in dBi)
+
+mprintf("The half power beam width is %d degrees", hpbw)
+mprintf("\nThe axial ratio is %.2f",ax_rat)
+mprintf("\nThe gain is %d or %.1f dBi",gain,gain_db)
diff --git a/3773/CH8/EX8.3/Ex8_3.sce b/3773/CH8/EX8.3/Ex8_3.sce
new file mode 100644
index 000000000..0e809d417
--- /dev/null
+++ b/3773/CH8/EX8.3/Ex8_3.sce
@@ -0,0 +1,21 @@
+//Chapter 8: Helical Antennas
+//Example 8-5.3
+clc;
+
+//Variable Initialization
+n = 10.0    //Number of turns (unitless)
+S = 0.236   //Spacing between turns (lambda)
+n_a = 4.0   //Number of helical antennas in the array (unitless)
+
+//Calculation
+D = 12*n*S  //Directivity of a single antenna(unitless)
+Ae = D/(4*%pi)   //Effective aperture (lambda^2)
+
+A = sqrt(Ae)    //Area of square/spacing between helixes (lambda)
+Ae_total = Ae*n_a   //Total effective aperture (lambda^2)
+D_array = (4*%pi*Ae_total)   //Directivity of the array (unitless)
+D_array_db = 10*log10(D_array)  //Directivity of the array (dBi)
+
+//Result
+mprintf("The best spacing between the helixes is %.1f lambda",A)
+mprintf("\nThe directivity of the array is %d or %.1f dBi",D_array,D_array_db)
diff --git a/3773/CH8/EX8.4/Ex8_4.sce b/3773/CH8/EX8.4/Ex8_4.sce
new file mode 100644
index 000000000..ea4a96700
--- /dev/null
+++ b/3773/CH8/EX8.4/Ex8_4.sce
@@ -0,0 +1,21 @@
+//Chapter 8: Helical Antennas
+//Example 8-16.1
+clc;
+
+//Variable Initialization
+gain = 24.0   //Gain (dB)
+alpha = 12.7    //Pitch angle (degrees)
+c_lambda = 1.05 //Circumference (lambda)
+s_lambda = 0.236    //Spacing between turns (lambda)
+
+//Calculation
+D = 10**(gain/10)   //Directivity (unitless)
+L = D/(12*(c_lambda**2))    //Helix length (lambda)
+n = L/s_lambda              //Number of turns (unitless)
+D = D/4             //Directivity for four 20-turn helixes(unitless)
+Ae = D/(4*%pi)       //Effective aperture of each helix (lambda^2)
+
+//Result
+mprintf("The Axial length is %.0f lambda",L)
+mprintf("\nThe number of turns for the axial length is %d",n)
+mprintf("\nThe effective aperture for 20 turns is %.0f lambda square",Ae)