planeWaveExcitation

Create plane wave excitation environment for antenna or array

Description

The planeWaveExcitation object creates an environment where a plane wave excites an antenna or array. Plane wave excitation is a scattering solution that solves the receiving antenna problem. By default, the antenna element is a dipole. The dipole is excited using a plane wave that travels along the positive x-axis having a z-polarization.

Creation

Syntax

h = planeWaveExcitation

h = planeWaveExcitation(Name,Value)

Description

h = planeWaveExcitation creates an environment where a plane wave excites the antenna or array. By default, the plane wave excites a dipole antenna.

h = planeWaveExcitation(Name,Value) returns a planeWaveExcitation environment, with additional properties specified by one or more name-value pair arguments. Name is the property name and Value is the corresponding value. You can specify several name-value pair arguments in any order as Name1, Value1, ..., NameN, ValueN. Properties not specified retain their default values.

Properties

Element — Antenna or array element

dipole (default) | object handle

Antenna or array element, specified as an object handle.

Example: 'Element',linearArray

Direction — Incidence of plane wave

[1 0 0] (default) | three-element real vector

Incidence of plane wave, specified as a three-element real vector.

Example: 'Direction',[0 0 1]

Data Types: double

Polarization — Polarization of incident electric field

[0 0 1] (default) | three-element complex vector

Polarization of incident electric field in x, y, and z components, specified as a three-element complex vector.

Example: 'Polarization',[0 1 0]

Data Types: double

Object Functions

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
EHfields	Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
mesh	Mesh properties of metal or dielectric antenna or array structure
meshconfig	Change mesh mode of antenna structure
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
show	Display antenna or array structure; Display shape as filled patch

Examples

Default Plane Wave Excitation

Excite a dipole antenna using a plane wave and view it.

h = planeWaveExcitation;
show(h)

The blue arrow shows the direction of propagation of the plane wave. By default, the direction is along the x-axis. The pink arrow shows polarization of the plane wave. By default, the polarization is perpendicular to the direction of propagation i.e. along the z-axis.

Feed Current of Antenna Excited By Plane Wave.

Excite a dipole antenna using plane wave. Calculate the feed current at 70 MHz.

h = planeWaveExcitation
cur = feedCurrent(h, 70e6)

h = 

  planeWaveExcitation with properties:

         Element: [1×1 dipole]
       Direction: [1 0 0]
    Polarization: [0 0 1]


cur =

   0.0179 - 0.0040i

Current Distribution On Antenna

Excite a dipole antenna using a plane wave. The polarization of the wave is along the z-axis and the direction of propagation is along the negative x-axis. View the antenna.

p = planeWaveExcitation('Element', dipole, 'Direction', [-1 0 0], 'Polarization', [0 0 1]);
show(p);

Plot the current distribution on the dipole antenna at 70 MHz.

current(p, 70e6);

Antenna Excited By Plane Wave In Arbitrary Direction

Consider a dipole excited by a plane wave.

p = planeWaveExcitation;
p.Direction = [0 1 1];
show(p)

If you use the above option, any analysis of this antenna will error out as the polarization and direction vector are not orthogonal to each other.

Use the cross-product function to find the appropriate polarization direction of such a wave.

p = planeWaveExcitation;
p.Polarization = cross(p.Direction, [0 1 1]);
show(p);

Calculate the current distribution of the antenna.

current(p,75e6);

References

[1] Balanis, C. A. Antenna Theory. Analysis and Design. 3rd Ed. Hoboken, NJ: John Wiley & Sons, 2005.