waveguideSlotted

Create slotted waveguide antenna

Description

The default waveguideSlotted object creates a slotted waveguide resonating around 2.4 GHz. 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(PropertyName=Value)

Description

ant = waveguideSlotted creates a slotted waveguide on the xy- plane with default property values. The default dimensions are chosen for an operating frequency of around 2.4 GHz.

ant = waveguideSlotted(PropertyName=Value) sets properties using one or more name–value arguments. PropertyName is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as PropertyName1=Value1,...,PropertyNameN=ValueN. Properties that you do not specify, retain their default values.

For example, ant = waveguideSlotted(Height=1) creates a slotted waveguide with a height of 1 meter.

Properties

Length — Length of waveguide

0.8060 (default) | real-valued scalar

Length of the waveguide, specified as a real-valued scalar in meters. Length is calculated as number of slots times the wavelength.

Example: 0.760

Data Types: double

Width — Width of waveguide

0.0857 (default) | real-valued scalar

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

Example: 0.0840

Data Types: double

Height — Height of waveguide

0.0428 (default) | real-valued scalar

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

Example: 0.0340

Data Types: double

NumSlots — Number of slots

8 (default) | scalar integer

Number of slots, specified as a scalar integer.

Example: 7

Data Types: double

Slot — Shape of slots

antenna.Rectangle object (default) | 2-D shape object

Shape of waveguide slot, specified as one of the following objects:

• antenna.Circle

• antenna.Polygon

• antenna.Rectangle

• antenna.Ellipse

• antenna.Triangle

Example: antenna.Rectangle(Length=0.035)

Data Types: double

SlotToTop — Distance from closed face edge to top slot center

0.0403 (default) | real-valued scalar

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

Example: 0.0503

Data Types: double

SlotSpacing — Space between centers of two adjacent slots

0.0806 (default) | real scalar | real vector

Spacing between the centers of two adjacent slots, specified as a real-valued scalar for uniform spacing or real-valued vector of length NumSlots-1 for non-uniform spacing in meters.

Example: 0.0906

Example: [0.0806 0.0906]

Data Types: double

SlotOffset — Slot displacement from centreline of width of waveguide to center of slot

0.0123 (default) | real-valued scalar | real-valued vector

Slot displacement from the center line of the width of the waveguide to the center of the slot, specified as a real-valued scalar for uniform offset or vector of size of 1-by-n where, n < NumSlots for non-uniform offset in meters.

Example: 0.0560

Example: [0.0560 0.0610]

Data Types: double

SlotAngle — Slot angle

0 (default) | real-valued scalar | real-valued vector

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.

When you specify SlotAngle as a vector, it must have a size of 1-by-n where, n <= NumSlots.

Example: 20

Example: [20 10]

Data Types: double

ClosedWaveguide — Plate or cover to close waveguide

0 (default) | 1

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

Example: 1

Data Types: double

FeedHeight — Height of feed

0.0310 (default) | real-valued scalar

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

Example: 0.0210

Data Types: double

FeedWidth — Width of feed

0.0020 (default) | real-valued scalar

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

Example: 0.0300

Data Types: double

FeedOffset — Signed distances from origin

[-0.3627 0] (default) | two-element vector

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: [-0.3627 0]

Data Types: double

Conductor — Type of metal

metal("PEC") (default) | metal object

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

Example: metal("Copper")

Load — Lumped elements

[1x1 lumpedElement] (default) | lumpedElement object

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

Example: lumpedElement(Impedance=75)

Tilt — Tilt angle of antenna

0 (default) | scalar | vector

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

Example: 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.

Data Types: double

TiltAxis — Tilt axis of antenna

[1 0 0] (default) | three-element vector | 2-by-3 matrix | "X" | "Y" | "Z"

Tilt axis of the antenna, specified as one of these values:

• 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, specified as a 2-by-3 matrix corresponding to two three-element vectors of Cartesian coordinates. In this case, the antenna rotates around the line joining the two points.

• "x", "y", or "z" to describe a rotation about the x-, y-, or z-axis, respectively.

For more information, see Rotate Antennas and Arrays.

Example: [0 1 0]

Example: [0 0 0;0 1 0]

Example: "Z"

Data Types: double | string

Object Functions

axialRatio	Calculate and plot axial ratio of antenna or array
bandwidth	Calculate and plot absolute bandwidth of antenna or array
beamwidth	Beamwidth of antenna
charge	Charge distribution on antenna or array surface
current	Current distribution on antenna or array surface
design	Create antenna, array, or AI-based antenna resonating at specified frequency
EHfields	Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
efficiency	Calculate and plot radiation efficiency of antenna or array
feedCurrent	Calculate current at feed for antenna or array
impedance	Calculate and plot input impedance of antenna or scan impedance of array
info	Display information about antenna, array, or platform
memoryEstimate	Estimate memory required to solve antenna or array mesh
mesh	Generate and view mesh for antennas, arrays, and custom shapes
meshconfig	Change meshing mode of antenna, array, custom antenna, custom array, or custom geometry
msiwrite	Write antenna or array analysis data to MSI planet file
optimize	Optimize antenna and array catalog elements using SADEA or TR-SADEA algorithm
pattern	Plot radiation pattern of antenna, array, or embedded element of array
patternAzimuth	Azimuth plane radiation pattern of antenna or array
patternElevation	Elevation plane radiation pattern of antenna or array
peakRadiation	Calculate and mark maximum radiation points of antenna or array on radiation pattern
rcs	Calculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequency	Calculate and plot resonant frequency of antenna
returnLoss	Calculate and plot return loss of antenna or scan return loss of array
show	Display antenna, array structures, shapes, or platform
sparameters	Calculate S-parameters for antenna or array
stlwrite	Write mesh information to STL file
vswr	Calculate and plot voltage standing wave ratio (VSWR) of antenna or array element

Examples

Default Slotted Waveguide Antenna and Radiation Pattern

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: [1×1 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: [1×1 metal]
               Tilt: 0
           TiltAxis: [1 0 0]
               Load: [1×1 lumpedElement]

show(ant)

Plot the radiation pattern of the antenna at 2.45 GHz.

pattern(ant, 2.45e9)

Impedance and S-Parameters of Custom Slotted Waveguide Antenna

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".

Version History

Introduced in R2019b