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waveguideSlotted

Create slotted waveguide antenna

Since R2019b

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Description

The waveguideSlotted object creates a slotted waveguide antenna. There are different types of slotted waveguides, including longitudinal slots, transversal slots, center inclined slots, inclined slots, and inclined slots cut into a narrow wall. Slotted waveguide antennas are used in navigation radar as an array fed by a waveguide.

Creation

Syntax

ant = waveguideSlotted
ant = waveguideSlotted(Name,Value)

Description

example

ant = waveguideSlotted creates a slotted waveguide antenna on the xy- plane. The circumference of the antenna is chosen for an operating frequency of 2.45 GHz.

example

ant = waveguideSlotted(Name,Value) sets properties using one or more name-value pairs. For example, ant = waveguideSlotted('Height',1) creates a slotted waveguide with a height of 1 meter.

Properties

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Length of the waveguide (n times lambda), specified as a real-valued scalar in meters. n is the number of slots in the waveguide.

Example: 'Length',0.760

Example: ant.Length = 0.760

Data Types: double

Width of the waveguide (a), specified as a real-valued scalar in meters.

Example: 'Width',0.0840

Example: ant.Width = 0.0840

Data Types: double

Height of the waveguide (b), specified as a real-valued scalar in meters. Please see image in Width property.

Example: 'Height',0.0340

Example: ant.Height = 0.0340

Data Types: double

Number of slots (n), specified as a scalar integer.

Example: 'Numslots',7

Example: ant.Numslots = 7

Data Types: double

Shape of waveguide slot, specified as one of the following objects: antenna.Circle, antenna.Polygon, antenna.Rectangle, and antenna.Ellipse.

Example: 'Slot',antenna.rectangle['Length',0.035]

Example: ant.Slot = antenna.rectangle['Length',0.035]

Data Types: double

Distance from the closed face edge to the top slot center, specified as a real-valued scalar in meters.

Example: 'SlotToTop',0.0503

Example: ant.SlotToTop = 0.0503

Data Types: double

Space between the centers of two adjacent slots, specified as a real-valued scalar in meters.

Example: 'SlotSpacing',0.0906

Example: ant.SlotSpacing = 0.0906

Data Types: double

Slot displacement from the centreline of the width of the waveguide to the center of the slot, specified as a real-valued scalar or vector in meters.

Note

If SlotOffset is a vector, it can be the size of 1-by-n where, n < NumSlots.

Example: 'SlotOffset',0.0560

Example: ant.SlotOffset = 0.0560

Data Types: double

Slot angle, specified as a real-valued scalar in degrees or a vector with each element unit in degrees. In slotted waveguide the slots are in pairs. You use a vector when you want one slot in the pair to be tilted at a different angle form the other. It varies from - 180o to 180o.

Note

If SlotAngle is a vector, it can be the size of 1-by-n where, n <= NumSlots.

Example: 'SlotAngle',[20 10]

Example: ant.SlotAngle = [20 10]

Data Types: double

Plate to close the open-ended side, specified as 0 for open waveguide and 1 for closed waveguide.

Example: 'ClosedWaveguide',1

Example: ant.ClosedWaveguide = 1

Data Types: double

Height of the feed, specified as a real-valued scalar in meters.

Example: 'FeedHeight',0.0210

Example: ant.FeedHeight = 0.0210

Data Types: double

Width of the feed, specified as a real-valued scalar in meters.

Example: 'FeedWidth',0.0300

Example: ant.FeedWidth = 0.0300

Data Types: double

Signed distances from the origin measured along the length and width of the waveguide, specified as a two-element vector with each element in meters.

Example: 'FeedOffset',[-0.3627 0]

Example: ant.FeedOffset = [-0.3627 0]

Data Types: double

Type of the metal used as a conductor, specified as a metal material object. You can choose any metal from the MetalCatalog or specify a metal of your choice. For more information, see metal. For more information on metal conductor meshing, see Meshing.

Example: m = metal('Copper'); 'Conductor',m

Example: m = metal('Copper'); ant.Conductor = m

Lumped elements added to the antenna feed, specified as a lumped element object. You can add a load anywhere on the surface of the antenna. By default, the load is at the feed. For more information, see lumpedElement.

Example: 'Load',lumpedelement. lumpedelement is the object for the load created using lumpedElement.

Example: ant.Load = lumpedElement('Impedance',75)

Tilt angle of the antenna, specified as a scalar or vector with each element unit in degrees. For more information, see Rotate Antennas and Arrays.

Example: Tilt=90

Example: Tilt=[90 90],TiltAxis=[0 1 0;0 1 1] tilts the antenna at 90 degrees about the two axes defined by the vectors.

Note

The wireStack antenna object only accepts the dot method to change its properties.

Data Types: double

Tilt axis of the antenna, specified as:

  • Three-element vector of Cartesian coordinates in meters. In this case, each coordinate in the vector starts at the origin and lies along the specified points on the X-, Y-, and Z-axes.

  • Two points in space, each specified as three-element vectors of Cartesian coordinates. In this case, the antenna rotates around the line joining the two points in space.

  • A string input describing simple rotations around one of the principal axes, 'X', 'Y', or 'Z'.

For more information, see Rotate Antennas and Arrays.

Example: TiltAxis=[0 1 0]

Example: TiltAxis=[0 0 0;0 1 0]

Example: TiltAxis = 'Z'

Data Types: double

Object Functions

showDisplay antenna, array structures or shapes
axialRatioAxial ratio of antenna
beamwidthBeamwidth of antenna
chargeCharge distribution on antenna or array surface
currentCurrent distribution on antenna or array surface
designDesign prototype antenna or arrays for resonance around specified frequency
EHfieldsElectric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
efficiencyRadiation efficiency of antenna
impedanceInput impedance of antenna; scan impedance of array
meshMesh properties of metal, dielectric antenna, or array structure
meshconfigChange mesh mode of antenna structure
optimizeOptimize antenna or array using SADEA optimizer
patternRadiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
patternAzimuthAzimuth pattern of antenna or array
patternElevationElevation pattern of antenna or array
rcsCalculate and plot radar cross section (RCS) of platform, antenna, or array
returnLossReturn loss of antenna; scan return loss of array
sparametersCalculate S-parameter for antenna and antenna array objects
vswrVoltage standing wave ratio of antenna

Examples

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Open Live Script

Create and view a slotted waveguide antenna with default property values.

ant = waveguideSlotted
ant = 
  waveguideSlotted with properties:

             Length: 0.8060
              Width: 0.0857
             Height: 0.0428
           NumSlots: 8
               Slot: [1x1 antenna.Rectangle]
          SlotToTop: 0.0403
        SlotSpacing: 0.0806
         SlotOffset: 0.0123
          SlotAngle: 0
          FeedWidth: 0.0020
         FeedHeight: 0.0310
         FeedOffset: [-0.3627 0]
    ClosedWaveguide: 0
          Conductor: [1x1 metal]
               Tilt: 0
           TiltAxis: [1 0 0]
               Load: [1x1 lumpedElement]


show(ant)

Figure contains an axes object. The axes object with title waveguideSlotted antenna element, xlabel x (mm), ylabel y (mm) contains 5 objects of type patch, surface. These objects represent PEC, feed.

Plot the radiation pattern of the antenna at 2.45 GHz.

pattern(ant, 2.45e9)

Figure contains an axes object and other objects of type uicontrol. The axes object contains 5 objects of type patch, surface.

Open Live Script

Create a slotted waveguide antenna with the following dimensions.

 ant = waveguideSlotted('Length',806e-3,'Width',94e-3, 'NumSlots',8,...
      'Height',44e-3,'Slot',antenna.Rectangle('Length',53e-3,'Width',6.5e-3),'SlotToTop',40.3e-3,...
      'SlotSpacing',80.6e-3,'SlotOffset',10e-3,'FeedHeight',31e-3, ...
      'FeedOffset',[-362.7e-3 0],'FeedWidth',2e-3);
show (ant)

Figure contains an axes object. The axes object with title waveguideSlotted antenna element, xlabel x (mm), ylabel y (mm) contains 5 objects of type patch, surface. These objects represent PEC, feed.

Plot impedance and S-parameters from 2.2 GHz to 2.8 GHz.

freq = 2.2e9:0.025e9:2.8e9;
figure;
impedance(ant,freq);

Figure contains an axes object. The axes object with title Impedance, xlabel Frequency (GHz), ylabel Impedance (ohms) contains 2 objects of type line. These objects represent Resistance, Reactance.

s = sparameters(ant,freq);
figure;
rfplot(s);

Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Magnitude (dB) contains an object of type line. This object represents dB(S_{11}).

References

[1] Perovic, Una. " Investigation of Rectangular, Unidirectional, Horizontally Polarized Waveguide Antenna with Longitudinal Slotted Arrays Operating at 2.45 GHz".

Version History

Introduced in R2019b

See Also

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