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')

Input Arguments

object — Antenna or array object

scalar handle

Antenna or array object, specified as a scalar handle.

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 Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'scale','log10'

'scale' — Scale to visualize charge distribution

string (default) | function handle

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

Data Types: char | function_handle

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.