waveguideSlotted

Create slotted waveguide antenna

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

Description

example

ant = waveguideSlotted creates a slotted waveguide antenna on the X-Y 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.

Output Arguments

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Slotted waveguide antenna, returned as a waveguideSlotted object.

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.

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 in meters.

Example: 'SlotOffset',0.0560

Example: ant.SlotOffset = 0.0560

Data Types: double

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

Example: 'SlotAngle',[20 10]

Example: ant.SlotOffset = [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

Lumped elements added to the antenna feed, specified as a lumped element object handle. 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 handle 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 degree about two axes, defined by vectors.

Data Types: double

Tilt axis of the antenna, specified as:

  • Three-element vectors of Cartesian coordinates in meters. In this case, each 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: ant.TiltAxis = 'Z'

Object Functions

showDisplay antenna or array structure; Display shape as filled patch
axialRatioAxial ratio of antenna
beamwidthBeamwidth of antenna
chargeCharge distribution on metal or dielectric antenna or array surface
currentCurrent distribution on metal or dielectric antenna or array surface
designDesign prototype antenna or arrays for resonance at specified frequency
EHfieldsElectric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
impedanceInput impedance of antenna; scan impedance of array
meshMesh properties of metal or dielectric antenna or array structure
meshconfigChange mesh mode of antenna structure
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
returnLossReturn loss of antenna; scan return loss of array
sparametersS-parameter object
vswrVoltage standing wave ratio of antenna

Examples

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

show(ant)

Plot the radiation pattern of the antenna at 2.45 GHz.

pattern(ant, 2.45e9)

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)  

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

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

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

References

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

Introduced in R2019b