Laboratory work # 3 Theme: Design and analyze dipole antennas using the Antenna Designer app Purpose

Object Functions

Object function

show	Display antenna or array structure; display shape as filled patch
info	Display information about antenna or array
axialRatio	Axial ratio of antenna
beamwidth	Beamwidth of antenna
charge	Charge distribution on metal or dielectric antenna or array surface
current	Current distribution on metal or dielectric antenna or array surface
design	Design prototype antenna or arrays for resonance at specified frequency
EHfields	Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
impedance	Input impedance of antenna; scan impedance of array
mesh	Mesh properties of metal or dielectric antenna or array structure
meshconfig	Change mesh mode of antenna structure
optimize	Optimize antenna or array using SADEA optimizer
pattern	Radiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
patternAzimuth	Azimuth pattern of antenna or array
patternElevation	Elevation pattern of antenna or array
returnLoss	Return loss of antenna; scan return loss of array
sparameters	S-parameter object
vswr	Voltage standing wave ratio of antenna

Create and view a dipole with 2 m length and 0.5 m width.

d = dipole('Width',0.05)

d =

dipole with properties:
Length: 2

Width: 0.0500

FeedOffset: 0

Tilt: 0

TiltAxis: [1 0 0]

Load: [1x1 lumpedElement]

show(d)

Impedance of Dipole Antenna

View MATLAB Command

Calculate the impedance of a dipole over a frequency range of 50 MHz - 100 MHz.

d = dipole('Width',0.05);

impedance(d,linspace(50e6,100e6,51))

Infinite Reflector Backed Dielectric Substrate Antenna

View MATLAB Command

Design a dipole antenna backed by a dielectric substrate and an infinite reflector.

Create a dipole antenna of length, 0.15 m, and width, 0.015 m.

d = dipole('Length',0.15,'Width',0.015, 'Tilt',90,'TiltAxis',[0 1 0]);

Create a reflector using the dipole antenna as an exciter and the dielectric, teflon as the substrate.

t = dielectric('Teflon')

t =

dielectric with properties:

Name: 'Teflon'

EpsilonR: 2.1000

LossTangent: 2.0000e-04

Thickness: 0.0060

For more materials see catalog
rf = reflector('Exciter',d,'Spacing',7.5e-3,'Substrate',t);

Set the groundplane length of the reflector to inf. View the structure.

rf.GroundPlaneLength = inf;

show(rf)

Calculate the radiation pattern of the antenna at 70 MHz.

pattern(rf,70e6)

References

[1] Balanis, C.A. Antenna Theory: Analysis and Design. 3rd Ed. New York: Wiley, 2005.

[2] Volakis, John. Antenna Engineering Handbook, 4th Ed. New York: Mcgraw-Hill, 2007.