Telecommunications

JBCardenas © 1982

Com3 1Q1516 Antenna Design

JBC © 198 v A2,2

Key design requirements1. Provide the theoretical computations of shapes and geometries

with matching and clear illustrations2. Provide the wire geometries input to NEC for all configurations3. You may have to configure curves with short sections of linear

wire, compute the metric diameter of the 10AWG wire4. A linear wire section should have at least 3 segments5. Package report concisely, e.g. side by side comparisons of 3D

and 2D plots, with 3 D antenna geometry, indicate gain and beamwidth for each pattern

6. In addition to the profiles, make sure to include the wire diagrams and orient all diagrams so that it is clearly perceived by the reader, if necessary use more than one illustration for a particular configuration

7. Simulation is easy, the difficult part is the math of steps 1 and 2. Remember garbage in garbage out.

8. Hard copy final report, short discussion of theoretical computations, optimization results, final result and comparative analysis

9. Soft copy to include all input data for the simulator, a user guide (notepad) if it will fit CD, an installation package.

10. X-axis propagation axis, Y-axis horizontal parallel to dipole elements, center signal source.

Telecommunications

JBCardenas © 1982

Com3 1Q1516 Antenna Design

JBC © 198 v A2,2

Design objective: Design an antenna for 476 MHz with one driven dipole element, a parasitic reflector and a dipole director 0.01 wavelength from driven element. Optimize design (gain) by varying the 0.01 distance. Use AWG8 solid bare copper wire as wire element. Provide 2D 3D radiation pattern, gain, beamwidth

Sensitivity analysis: when optimum is foundUse a reflector comprised of wire elementsUse a reflector comprised of sheet metalCheck performance at +/- 10%, 20% of 476 MHz

Comparative analysis: vs a beam antenna comprised of one dipole reflector parasitic and one dipole director parasitic both 0.01 wavelengths away from driven element

Telecommunications

JBCardenas © 1982

1Q1516 model 1

JBC © 198 v A2,2

Driven dipole for 476 MHz at the focus of a parabolic reflectorParabolic reflector is a section of a cylindrical parabola, at least 5

parabolic elements; at least 5 linear elements to comprise the mesh.

The diameter of the mouth of the parabola and the length of the cylinder > than length of driven dipole

The driven dipole should be in the plane of the mouth of the reflector (or inside)

Try to make the focal length as near as 0.01 wavelength as possible

Provide a parasitic director 0.01 wavelengths away from driven element

Optimization: vary the 0.01 director distance to get best gain

Telecommunications

JBCardenas © 1982

1Q1516 model 2

JBC © 198 v A2,2

Driven dipole for 476 MHz at the focus of a parabolic reflectorParabolic reflector is a section of a full parabola, comprised of at

least 3 parabolic wire elements, and 3 circular (or hexagonal) wire elements.

The diameter of the mouth of the parabola > length of driven dipole

The driven dipole should be in the plane of the mouth of the reflector (or inside)

Try to make the focal length as near as 0.01 wavelengths as possible

Provide a parasitic director 0.01 wavelengths away from driven element

Optimization: vary the 0.01 director distance (small increments) to get best gain

Telecommunications

JBCardenas © 1982

1Q1516 model 3

JBC © 198 v A2,2

Driven dipole for 476 MHz 0.01 wavelength from center of corner reflector

Corner reflector comprised of at least 15 linear wire elements to comprise the mesh (or 5 V elements)

The width and height of the mouth of the reflector > length of driven dipole

The driven dipole should be in the plane of the mouth of the reflector (or inside)

Provide a parasitic director 0.01 wavelengths away from driven element

Optimization 1: vary the angle of the reflector to get best gain start at 90 degrees, then +/- a few degrees.

Optimization 2: Once optimization 1 is attained, vary the 0.01 director distance to get best gain