current

Current distribution on metal or dielectric antenna or array surface

Syntax

current(object,frequency)

i = current(object,frequency)

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

current(object,frequency,'dielectric')

i = current(object,frequency,'dielectric')

i = current(___,Name,Value)

Description

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

i = current(object,frequency) returns the x, y, z components of the current on the surface of an antenna or array object, at a specified frequency.

[i,p] = charge(object,frequency) returns the x, y, z components of the current on the surface of an antenna or array object, at a specified frequency and at the point in which the current calculation is performed.

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

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

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

Examples

Calculate and Plot Current Distribution on Antenna Surface

Calculate and plot the current distribution for a circular loop antenna at 70MHz frequency.

 h = loopCircular;
 current(h,70e6);

Calculate Current Distribution of Array

Calculate the current distribution of a default rectangular array at 70MHz frequency.

h = rectangularArray;
i = current(h,70e6)

i = 3×160 complex

   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i
   0.0009 + 0.0020i   0.0013 + 0.0025i  -0.0002 - 0.0012i   0.0003 + 0.0013i   0.0004 + 0.0015i  -0.0005 - 0.0015i  -0.0014 - 0.0025i  -0.0009 - 0.0020i   0.0015 + 0.0027i  -0.0015 - 0.0027i   0.0030 + 0.0051i  -0.0020 - 0.0034i   0.0017 + 0.0030i  -0.0017 - 0.0030i  -0.0000 - 0.0041i   0.0000 + 0.0021i  -0.0007 - 0.0017i   0.0007 + 0.0017i   0.0011 + 0.0023i  -0.0011 - 0.0023i   0.0007 + 0.0017i  -0.0007 - 0.0018i   0.0005 + 0.0015i  -0.0005 - 0.0015i   0.0011 + 0.0022i   0.0003 + 0.0013i  -0.0009 - 0.0020i   0.0009 + 0.0020i  -0.0015 - 0.0027i   0.0016 + 0.0028i  -0.0002 - 0.0012i  -0.0011 - 0.0023i  -0.0016 - 0.0030i   0.0017 + 0.0029i   0.0001 + 0.0021i  -0.0000 - 0.0041i   0.0030 + 0.0051i  -0.0013 - 0.0025i  -0.0020 - 0.0035i   0.0013 + 0.0025i   0.0009 + 0.0020i   0.0013 + 0.0025i  -0.0002 - 0.0012i   0.0003 + 0.0013i   0.0005 + 0.0015i  -0.0005 - 0.0015i  -0.0013 - 0.0025i  -0.0009 - 0.0020i   0.0015 + 0.0027i  -0.0015 - 0.0027i
   0.0562 + 0.1041i   0.0428 + 0.0763i   0.0659 + 0.1334i   0.0649 + 0.1280i   0.0641 + 0.1250i   0.0621 + 0.1188i   0.0373 + 0.0658i   0.0523 + 0.0956i   0.0343 + 0.0603i   0.0280 + 0.0487i   0.0031 + 0.0054i   0.0137 + 0.0235i   0.0176 + 0.0302i   0.0246 + 0.0427i   0.0662 + 0.1423i   0.0661 + 0.1358i   0.0580 + 0.1081i   0.0609 + 0.1154i   0.0453 + 0.0813i   0.0501 + 0.0911i   0.0608 + 0.1154i   0.0579 + 0.1079i   0.0621 + 0.1188i   0.0641 + 0.1251i   0.0502 + 0.0910i   0.0649 + 0.1281i   0.0523 + 0.0955i   0.0562 + 0.1040i   0.0344 + 0.0603i   0.0280 + 0.0487i   0.0659 + 0.1334i   0.0455 + 0.0816i   0.0247 + 0.0427i   0.0177 + 0.0303i   0.0661 + 0.1358i   0.0662 + 0.1422i   0.0032 + 0.0054i   0.0373 + 0.0658i   0.0138 + 0.0236i   0.0429 + 0.0765i   0.0562 + 0.1041i   0.0428 + 0.0763i   0.0659 + 0.1334i   0.0649 + 0.1280i   0.0641 + 0.1250i   0.0621 + 0.1188i   0.0373 + 0.0658i   0.0523 + 0.0956i   0.0343 + 0.0602i   0.0280 + 0.0487i

Current 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]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(pm)

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

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

Logarithmic Current Distribution on Antenna Surface

Create a default pifa (planar inverted F antenna).

ant = pifa;

Visualize the current distribution on the pifa antenna in using log function scale.

current(ant,1.75e9,'scale','log')

Input Arguments

object — Antenna or array object

scalar handle

Antenna or array object, specified as a scalar handle.

frequency — Frequency used to calculate current distribution

scalar in Hz

Frequency to calculate current 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 current distribution

string (default) | function handle

Scale to visualize the current 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

i — x, y, z components of current distribution

3-by-n complex matrix in A/m

x, y, z components of current distribution, returned as a 3-by-n complex matrix in A/m. The value of the current 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.