charge

Charge distribution on metal or dielectric antenna or array surface

Syntax

charge(object,frequency)

c = charge(object,frequency)

[c,p] = charge(object,frequency)

charge(object,frequency,'dielectric')

c = charge(object,frequency,'dielectric')

c = charge(___,Name,Value)

Description

charge(object,frequency) calculates and plots the absolute value of the charge on the surface of an antenna or array object surface at a specified frequency.

c = charge(object,frequency) returns a vector of charges in C/m on the surface of an antenna or array object, at a specified frequency.

[c,p] = charge(object,frequency) returns a vector of charges in C/m on the surface of an antenna or array object, at a specified frequency and at the point at which the charge calculation was performed.

charge(object,frequency,'dielectric') calculates and plots the absolute value of charge at a specified frequency value on the dielectric face of the antenna or array.

c = charge(object,frequency,'dielectric') returns the x, y, z components of the charge on the dielectric surface of an antenna or array object, at a specified frequency.

c = charge(___,Name,Value) calculates the charge on the surface of an antenna using additional name-value pairs.

Examples

Calculate and Plot Charge Distribution on Antenna Surface

Calculate and plot the charge distribution on a bowtieTriangular antenna at 70MHz frequency.

h = bowtieTriangular;
charge (h, 70e6);

Calculate Charge Distribution of Array

Calculate charge distribution of linear array at 70 MHz frequency.

h = linearArray;
h.NumElements = 4;
C = charge(h,70e6);

Charge Distribution On Microstrip Patch Antenna

Create a microstrip patch antenna using 'FR4' as the dielectric substrate.

d = dielectric('FR4');
pm = patchMicrostrip('Length',75e-3, 'Width',37e-3,                 ...
        'GroundPlaneLength',120e-3, 'GroundPlaneWidth',120e-3, ...
        'Substrate',d)

pm = 
  patchMicrostrip with properties:

               Length: 0.0750
                Width: 0.0370
               Height: 0.0060
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.1200
     GroundPlaneWidth: 0.1200
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0187 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(pm)

Plot the charge distribution on the antenna at a frequency of 1.67 GHz.

figure
charge(pm,1.67e9,'dielectric')

Logarithmic Charge Distribution on Antenna Surface

Create a default pifa (planar inverted F antenna).

ant = pifa;

Visualize the charge distribution on the pifa antenna in log10 scale.

charge(ant,1.75e9,'scale','log10')

View Sliced Charge Distribution Plot of Antenna

Create a default cylindrical dielectric resonator antenna. Plot the charge distribution of the antenna at 1GHz with the 'Slicer' argument set to 'on'.

ant = draCylindrical('ResonatorRadius',0.01);
charge(ant,1e9,'Slicer','on')

Select Enable slicer Mode. Then select a plane for the slice under Orientation.

Click on the plot and select a region to hide.

Click Hide Selected Region to view the desired slice.

Input Arguments

object — Antenna or array object

scalar

Antenna or array object, specified as a scalar.

frequency — Frequency used to calculate charge distribution

scalar in Hz

Frequency used to calculate charge distribution, specified as a scalar in Hz.

Example: 70e6

Data Types: double

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'scale','log10'

scale — Scale to visualize charge distribution

string (default) | function

Scale to visualize the charge distribution on the surface of the antenna, specified as a string or a function. The string values are: 'linear', 'log', 'log10'. By default, the value is 'linear'. The function can be of any mathematical function such as log, log10, cos, or sin.

Data Types: char | function

Slicer — Flag to enable or disable plot interactivity

0 (default) | 1 | 'off' | 'on'

Flag to enable or disable plot interactivity, specified as 'on' or 'off', or as numeric or logical 1(true) or 0(false). Setting this flag to 1 or 'on' opens a plot with the Slicer panel, where you can slice and view the desired cross section of the plot along the XY-, YZ-, and XZ- planes. Setting this flag to 0 or 'off' opens a plot without the Slicer panel.

Data Types: string | logical

Output Arguments

c — Complex charges

1-by-n vector in C/m

Complex charges, returned as a 1-by-n vector in C/m. This value is calculated on every triangle mesh or every dielectric tetrahedron face on the surface of an antenna or array.

p — Cartesian coordinates representing center of each triangle in mesh

3-by-n real matrix

Cartesian coordinates representing the center of each triangle in the mesh, returned as a 3-by-n real matrix.

Version History

Introduced in R2015a