measuredAntenna

Use measured pattern data as exciter for backing structures

Since R2023a

Description

The measuredAntenna object lets you perform port and field analysis on the measured field data of an antenna or array. You can import measured field data from a .txt file, .csv file, or .xlsx file to the MATLAB^® workspace and assign it to the relevant properties of this object. The field data includes Cartesian electric and embedded electric field components in V/m at the observation points, spherical coordinates of the observation points, the phase center, number of excitation ports, measurement frequencies, and S-parameters. The measuredAntenna object also lets you replace the physical exciter of the curved reflector antennas from the antenna catalog with measured field data of the exciter and perform fundamental analysis on the reflector antenna using the Physical Optics solver.

Creation

Syntax

m = measuredAntenna

m = measuredAntenna(Name=Value)

Description

m = measuredAntenna creates an antenna field data object with the x, y, and z-components of the electric field being 0.1 V/m across the observed direction.

m = measuredAntenna(Name=Value) creates a measured antenna object, with additional Properties specified by one or more name–value arguments. Name is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as Name1= Value1, ..., NameN=ValueN. Properties not specified retain their default values.

Properties

E — Magnitude of radiated electric field

[0.1 0.1 0.1] (default) | P-by-3-by-F matrix

Cartesian components of the electric field in V/m at observation points, specified as a P-by-3-by-F matrix. P represents the number of observation points and components are specified in [X Y Z] order. The default value is [0.1 0.1 0.1] V/m at a single observation point. F represents the number of frequencies over which the electric field is measured.

Example: E(:,:,1) = [0.5 0.3 0.7]

Example: E(1,:,:) = [0.1 0.1 0.1; 0.2 0.3 0.15;...0.5 0.45 0.35]

Data Types: double
Complex Number Support: Yes

Direction — Direction of radiated electric field

[0 90 100] (default) | P-by-3 matrix

Spherical coordinates of the observation points, specified as a P-by-3 matrix. P represents the number of observation points and the coordinates are specified as [Azimuth(degree) Elevation(degree) Radius(meter)]. The default value is a single observation point at [0 90 100].

Example: [30 60 200]

Example: [0 90 100; ...; 359 359 100]

Data Types: double

PhaseCenter — Phase center of measured antenna

[0 0 0.075] (default) | 1-by-3 vector

Cartesian coordinates of the phase center of the measured antenna in meter, specified as a 1-by-3 vector in [X Y Z] order. The default phase center is at [0 0 0.075]. Phase center is defined as a point in space from which, when emitted, the far-field phase fronts remain spherical in a certain angular area of interest. PhaseCenter denotes the average phase center of the incident electric field, E.

Example: [0 1 1]

Data Types: double

NumPorts — Number of excitation ports

1 (default) | positive scalar integer

Number of excitation ports in the measured antenna or array, specified as a positive scalar integer. Number of antenna ports specified in this property must be equal to the number of antenna ports in EmbeddedE property.

Example: 2

Data Types: double

FieldFrequency — Frequencies used to measure electric field

1e9 (default) | scalar | F-by-1 vector

Frequencies at which the electric field of the antenna or array was measured, specified as a scalar for a single frequency or a F-by-1 vector for multiple frequencies, where F is the number of frequencies.

Example: 1e9

Example: [1e9 1.25e9 1.5e9]

Data Types: double

FieldCoordinate — Coordinate system for field data

"rectangular" (default) | "polar"

Coordinate system for the measured field data, specified as a string amongst:

• rectangular - Cartesian coordinates, where the points are specified as [x y z].

• polar - Spherical coordinates, where the points are specified as [azimuth elevation radial].

Example: "polar"

Data Types: string

Azimuth — Azimuth angles used to measure electric field

0 (default) | scalar | A-by-1 vector

Azimuth angles used to measure electric field, specified as a scalar or A-by-1 vector in degrees, where A is the number of azimuth angles.

Example: [0:5:90]

Data Types: double

Elevation — Elevation angles used to measure electric field

90 (default) | scalar | E-by-1 vector

Elevation angles used to measure electric field, specified as a scalar or E-by-1 vector in degrees, where E is the number of elevation angles.

Example: [0:5:90]

Data Types: double

Sparameters — Scattering parameters of antenna or array

"[]" (default) | sparameters object

S-parameters for all excitation ports at each frequency, specified as a sparameters object.

Example: sparameters("sample.s2p")

Example: sparameters(dipole,70e6,50)

Example: sparameters(linearArray,140e6)

Data Types: double

EmbeddedE — Electric field of individual element in array

"[]" (default) | P-by-3-by-N-by-F 4-D array

Cartesian components (P-by-3) of embedded electric field magnitude in V/m when the FieldCoordinate is "rectangular", for each port (N) at each frequency (F) at each observation point in the Direction property, specified as a 4-D array. Number of points is defined by P.

When the FieldCoordinate is "polar", the three columns in P-by-3 matrix represent azimuth angle, elevation angle, and radial magnitude. Set NumPorts value greater than 1 to enable this property.

Example: Let EmbeddedE = emb in a rectangular coordinate system. To access the electric field data for a single port at a single frequency, use emb(:,:,1,1).

Data Types: double
Complex Number Support: Yes

TerminationImpedance — Termination impedance for array elements

50 (default) | real scalar

Impedance to terminate other ports except the excitation port while computing the embedded pattern, specified as a real scalar. Set NumPorts value greater than 1 to enable this property.

Example: 75

Data Types: double

AmplitudeTaper — Excitation amplitude of array elements in Volts

1 (default) | positive scalar | positive vector of size 1-by-NumPorts positive vector

Excitation amplitude of array elements in Volts, specified as one of these options:

• Positive scalar — Use this value to specify uniform amplitude across the individual elements.

• Positive vector of size 1-by-NumPorts — Use this value to specify non-uniform amplitude across the individual elements.

The default AmplitudeTaper is 1 Volt.

Example: 2

Example: [2 4]

Data Types: double

PhaseShift — Phase shift of array elements in degrees

0 (default) | numeric scalar | numeric vector of size 1-by-NumPorts

Phase shift of array elements in degrees, specified as one of these options:

• Numeric scalar — Use this value to specify uniform phase shift across the individual elements.

• Numeric vector of size 1-by-NumPorts — Use this value to specify non-uniform phase shift across the individual elements.

The default PhaseShift is zero degrees. PhaseShift values correspond to the respective excitation voltages of the individual elements in the array.

Example: 45

Example: [45 -45]

Data Types: double

CalculateTotalField — Option to calculate total electric field from embedded field data

false or 0 (default) | true or 1

Option to calculate the total electric field from embedded field data, specified as one of these options:

• Numeric or logical 0(false) — Use this value to disable this option.

• Numeric or logical 1(true) — Use this value to enable this option.

By default, this option is disabled. When this option is enabled, the EHfields and pattern functions use the calculated total electric field in their results.

Example: true

Data Types: logical

Object Functions

EHfields	Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
pattern	Plot radiation pattern and phase of antenna or array or embedded pattern of antenna element in array
sparameters	Calculate S-parameters for antenna or array

Note

When measuredAntenna is an input argument to the above functions:

• The EHfields function can be used only to visualize the E-field data contained in the E property of the measuredAntenna.

• The pattern function can have its Type argument set to only efield.

• The sparameters function plots the S-parameters when no output argument is specified or creates a sparameters object when an output argument is specified.

Examples

Excite Parabolic Reflector Using E-field Data

This example shows how to use the measured electric field data of a dipole antenna to excite a parabolic reflector structure. The example uses EHfields function to generate the electric field data. You can import the electric field data of any external antenna into the measuredAntenna object. The electric field magnitude is expressed in V/m and coordinates are expressed in meters and degrees.

Create Dipole antenna, save field data and plot electric field

Design a dipole antenna operating at 10 GHz. Save the complex E-field data of this dipole antenna in a variable.

freq = 10e9;
ant = design(dipole(Tilt=90,TiltAxis=[0 1 0]),freq);
E = EHfields(ant,freq)

E = 3×441 complex

  12.2492 +50.7204i  10.9830 +50.0817i   7.2868 +48.1070i   1.4638 +44.6408i  -5.9963 +39.4936i -14.4447 +32.5478i -23.1139 +23.9147i -31.1701 +14.1574i -37.7710 + 4.5564i -42.1360 - 2.7961i -43.6684 - 5.6012i -42.1360 - 2.7961i -37.7710 + 4.5564i -31.1701 +14.1574i -23.1139 +23.9147i -14.4447 +32.5478i  -5.9963 +39.4936i   1.4638 +44.6408i   7.2868 +48.1070i  10.9830 +50.0817i  12.2492 +50.7204i  12.2492 +50.7204i  11.1051 +50.1436i   7.7649 +48.3712i   2.5080 +45.2950i  -4.2156 +40.7988i -11.8109 +34.8519i -19.5772 +27.6408i -26.7579 +19.7300i -32.6013 +12.2039i -36.4360 + 6.6227i -37.7749 + 4.5369i -36.4360 + 6.6227i -32.6013 +12.2039i -26.7579 +19.7300i -19.5772 +27.6408i -11.8109 +34.8519i  -4.2156 +40.7988i   2.5080 +45.2950i   7.7649 +48.3712i  11.1051 +50.1436i  12.2492 +50.7204i  12.2492 +50.7204i  11.4228 +50.3047i   9.0112 +49.0475i   5.2258 +46.9296i   0.4051 +43.9584i  -5.0085 +40.2214i -10.5012 +35.9467i -15.5309 +31.5501i
   0.0191 + 0.0071i   0.0155 + 0.0116i   0.0115 + 0.0155i   0.0072 + 0.0187i   0.0027 + 0.0210i  -0.0020 + 0.0221i  -0.0065 + 0.0223i  -0.0106 + 0.0218i  -0.0137 + 0.0210i  -0.0158 + 0.0203i  -0.0165 + 0.0201i  -0.0158 + 0.0203i  -0.0137 + 0.0210i  -0.0106 + 0.0218i  -0.0065 + 0.0223i  -0.0020 + 0.0221i   0.0027 + 0.0210i   0.0072 + 0.0187i   0.0115 + 0.0155i   0.0155 + 0.0116i   0.0191 + 0.0071i   0.0191 + 0.0071i  -0.3208 - 0.2160i  -1.3069 - 0.9109i  -2.8600 - 2.1211i  -4.8516 - 3.8972i  -7.1112 - 6.2625i  -9.4357 - 9.1600i -11.6018 -12.3805i -13.3806 -15.4882i -14.5582 -17.8213i -14.9717 -18.6996i -14.5582 -17.8213i -13.3806 -15.4882i -11.6018 -12.3805i  -9.4357 - 9.1600i  -7.1112 - 6.2625i  -4.8516 - 3.8972i  -2.8600 - 2.1211i  -1.3069 - 0.9109i  -0.3208 - 0.2160i   0.0191 + 0.0071i   0.0191 + 0.0071i  -0.5280 - 0.3556i  -2.1176 - 1.4606i  -4.6137 - 3.3253i  -7.7981 - 5.9465i -11.3836 - 9.2543i -15.0340 -13.0573i -18.3899 -16.9940i
   0.0000 + 0.0001i  -7.2267 - 4.8924i -13.8167 - 9.7575i -19.1754 -14.4814i -22.7937 -18.7870i -24.2914 -22.1762i -23.4561 -23.9067i -20.2734 -23.0454i -14.9513 -18.7079i  -7.9486 -10.6411i   0.0000 + 0.0000i   7.9486 +10.6411i  14.9513 +18.7079i  20.2734 +23.0454i  23.4561 +23.9067i  24.2914 +22.1762i  22.7937 +18.7870i  19.1754 +14.4814i  13.8167 + 9.7575i   7.2267 + 4.8924i  -0.0000 - 0.0001i   0.0000 + 0.0001i  -6.8731 - 4.6457i -13.1344 - 9.2239i -18.2136 -13.5889i -21.6250 -17.4521i -23.0095 -20.3392i -22.1726 -21.5919i -19.1151 -20.4533i -14.0568 -16.3107i  -7.4547 - 9.1466i   0.0000 + 0.0000i   7.4547 + 9.1466i  14.0568 +16.3107i  19.1151 +20.4533i  22.1726 +21.5919i  23.0095 +20.3392i  21.6250 +17.4521i  18.2136 +13.5889i  13.1344 + 9.2239i   6.8731 + 4.6457i  -0.0000 - 0.0001i   0.0000 + 0.0001i  -5.8454 - 3.9358i -11.1561 - 7.7223i -15.4375 -11.1610i -18.2748 -13.9710i -19.3715 -15.7815i -18.5823 -16.1686i -15.9384 -14.7525i

Plot the electric field vectors of this dipole antenna.

fig = figure; 
EHfields(ant,freq,ViewField="E");

Extract coordinates of electric field points and pass field data to measuredAntenna

Extract the Cartesian coordinates of direction vectors from the electric field plot using quiver. Convert these Cartesian coordinates into spherical coordinates using cart2sph function.

quH = fig.Children(4).Children;
pts = [quH.XData;quH.YData;quH.ZData];
[phi,theta,radius] = cart2sph(pts(1,:),pts(2,:),pts(3,:));
dir = [rad2deg(phi)' 90-rad2deg(theta)' radius'];

Create a measuredAntenna object and pass the electric field data (in V/m.), spherical coordinates of the electric field points, and the phase center of the this field to the respective properties of the measuredAntenna object.

ms = measuredAntenna;
ms.E = E';
ms.Direction = dir;
lambda = 3e8/freq;
f = 5 * lambda;
ms.PhaseCenter = [0 0 f];
ms.FieldFrequency = freq;

Create parabolic reflector antenna with measuredAntenna as exciter

Create a parabolic reflector antenna with the measuredAntenna data as Exciter. Plot the radiation pattern of this antenna at 10 GHz.

back = reflectorParabolic;
back.Exciter = ms;
figure; 
pattern(back,10e9)

Import and Visualize Measured Radiation Pattern Data

This example shows how to import and analyze the measured pattern data of a linear array.

Import Measured Pattern Data

Define the frequency range of the data and number of antenna elements in the array. Import the data from a text file using readmatrix function.

The text file contains measured field data for a linear array of dipoles at 3 frequencies 1.6GHz, 2GHz, and 2.4GHz.

fRange = [1.6e9 2e9 2.4e9];
numAnt = 2;
patternData = readmatrix("MeasuredData.txt");
patternData

patternData = 2701×30 complex
102 ×

   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  -1.8000 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.7500 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.7000 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.6500 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.6000 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.5500 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.5000 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.4500 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.4000 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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  -1.3500 + 0.0000i   1.8000 + 0.0000i   0.1500 + 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
      ⋮

Extract the field data, direction data, and embedded field data from the imported data. Further, extract azimuth and elevation data from the direction data.

% E-field data
eField(:,:,1) = patternData(:,1:3);
eField(:,:,2) = patternData(:,4:6);
eField(:,:,3) = patternData(:,7:9);

% Direction, azimuth, and elevation data
dir = patternData(:,10:12);
az = dir(1:73,1);
el = dir(1:73:end,2);

% Embedded E-field data
embE(:,:,1,1) = patternData(:,13:15);
embE(:,:,2,1) = patternData(:,16:18);
embE(:,:,1,2) = patternData(:,19:21);
embE(:,:,2,2) = patternData(:,22:24);
embE(:,:,1,3) = patternData(:,25:27);
embE(:,:,2,3) = patternData(:,28:30);

Import and extract S-parameters data from Touchstone files.

% Import S-parameters data
sParamData1 = sparameters("Parameters_1.6ghz.s2p");
sParamData2 = sparameters("Parameters_2ghz.s2p");
sParamData3 = sparameters("Parameters_2.4ghz.s2p");

% Extract S-parameters data
sParam(:,:,1) = sParamData1.Parameters;
sParam(:,:,2) = sParamData2.Parameters;
sParam(:,:,3) = sParamData3.Parameters;
sParamFreq(:,1) = sParamData1.Frequencies;
sParamFreq(:,2) = sParamData2.Frequencies;
sParamFreq(:,3) = sParamData3.Frequencies;
sParam

sParam = 
sParam(:,:,1) =

   0.6991 - 0.5140i   0.0523 + 0.0366i
   0.0523 + 0.0366i   0.6991 - 0.5140i


sParam(:,:,2) =

   0.2076 - 0.0674i  -0.0918 - 0.1830i
  -0.0918 - 0.1830i   0.2076 - 0.0674i


sParam(:,:,3) =

   0.6581 + 0.2567i  -0.0490 + 0.0871i
  -0.0490 + 0.0871i   0.6581 + 0.2567i

sParamFreq

sParamFreq = 1×3
109 ×

    1.6000    2.0000    2.4000

s = sparameters(sParam,sParamFreq);

Assign Data to measuredAntenna

Assign the extracted data to a measuredAntenna object.

mesAnt = measuredAntenna(E=eField, Direction=dir, NumPorts=numAnt,...
                Azimuth=az, Elevation=el, FieldCoordinate="polar",...
                EmbeddedE=embE, FieldFrequency=fRange, Sparameters=s)

mesAnt = 
  measuredAntenna with properties:

                       E: [2701x3x3 double]
               Direction: [2701x3 double]
             PhaseCenter: [0 0 0.0750]
                NumPorts: 2
          FieldFrequency: [3x1 double]
         FieldCoordinate: "polar"
                 Azimuth: [-180 -175 -170 -165 -160 -155 -150 -145 -140 -135 -130 -125 -120 -115 -110 -105 -100 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 ... ] (1x73 double)
               Elevation: [180 175 170 165 160 155 150 145 140 135 130 125 120 115 110 105 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0]
             Sparameters: [1x1 sparameters]
          AmplitudeTaper: 1
              PhaseShift: 0
               EmbeddedE: [2701x3x2x3 double]
    TerminationImpedance: 50
     CalculateTotalField: 0

Visualize Measured Pattern Data

Plot the radiation pattern and electric field for this measuredAntenna at 2GHz, while plot S-parameters over the entire frequency range.

pattern(mesAnt,fRange(2),Type="efield")

EHfields(mesAnt,fRange(2))

sp = sparameters(mesAnt,fRange);
rfplot(sp)

Version History

Introduced in R2023a

R2024a: Calculate total electric field using embedded field data

Calculate the total electric field of an array from the embedded field, excitation amplitude, and phase shift of the individual antenna elements in the array. Use this calculated total electric field in the field analysis of the array using the pattern and EHfields functions.

R2023b: Perform field and port analysis on measured field data

Perform field and port analysis using pattern, EHfields, and sparameters on:

• The electric field and S-parameters data of an antenna

• The total electric field, embedded electric field, and S-parameters data of an array

measured at multiple frequencies.