Simulation of a 3D monopole antenna

Hi,

For the planar L-monopole shown below, how can make it 3D, that is, adding some height to the L, for example 2mm?

Thanks.

[Vinod Dwarapudi]

Hi Jaume

extrudeLinear and other geometry features in Antenna Toolbox can be used to thicken the monopole

clc;clearvars;

% create an invertedLcoplanar antenna

lco = invertedLcoplanar(Length=50e-3,Height=14e-3,...

GroundPlaneLength=100e-3,GroundPlaneWidth=100e-3);

figure;

impedance(lco,1.1e9:10e6:1.5e9); % running impedance to get default mesh info

m = mesh(lco);

% converting catalog element to pcbStack

p = pcbStack(lco);

layer1 = p.Layers{1};

layer1 = shape.Polygon('Vertices',layer1.Vertices);

% thickening the shape in negative z direction

thickness = 2e-3; % 2 mm

thickenedLayer = extrudeLinear(layer1,thickness,"Caps",true,"Direction",[0,0,-1]);

% meshing the structure with similar maxEdgeLength as catalog

figure;

mesh(thickenedLayer,'MaxEdgeLength',m.MaxEdgeLength);

% exporting mesh as points and triangles

[p1,t] = exportMesh(thickenedLayer);

% creating triangulation from points and triangles

tr=triangulation(t(:,1:3),p1);

% creating custom3D shape using triangulation

sh = shape.Custom3D(tr);

% creating custom antenna from custom shape

ant = customAntenna(Shape=sh);

% setting the feed location information from pcbStack

[~] = createFeed(ant,[p.FeedLocations(1:2) 0],1);

figure;

show(ant)

[Jaume]

Many thanks for the answer. WHat if I want only to extrude the horizontal part of the monopole and keep the vertical part and the ground plane 2d? Is that possible? And then, Can I add a substrate underneath havibg the same size as the GND + the clearance area of the monopole?

Answer 1

[Umar]

Hi @Jaume, Great question about adding thickness to your inverted-L coplanar antenna! I understand you want to add approximately 2mm of height to make it a true 3D structure. Unfortunately, the built-in invertedLcoplanar object in MATLAB's Antenna Toolbox creates zero-thickness planar geometries by design. The "Height" property in these catalog elements refers to the vertical arm length of the inverted-L shape, not the metal thickness. You cannot simply add physical thickness through property modifications. For your 2mm thickness requirement, you'll need to use the customAntennaStl approach: 1. Create your inverted-L geometry with actual 2mm thickness using CAD software (SolidWorks, Fusion 360, FreeCAD, or similar) 2. Export the model as an STL, STEP, or IGES file 3. Import into MATLAB using customAntennaStl: ant = customAntennaStl(FileName="inverted_L_2mm.stl", Units="mm"); createFeed(ant); % Opens interactive UI for feed placement show(ant); impedance(ant, frequency); The createFeed() function provides an interactive slicer tool that lets you visually select feeding edges on your 3D geometry, which is particularly helpful for complex structures. For detailed documentation and examples, see: https://www.mathworks.com/help/antenna/ref/customantennastl.html *Note:* For most RF applications, conductor thickness has minimal electromagnetic impact when it's much smaller than the wavelength. If you're modeling this for mechanical integration or visualization purposes, customAntennaStl is definitely the right approach. However, if you only need electromagnetic analysis, the planar model is typically sufficient. Hope this helps!

[Jaume]

Many thanks Umar. I will try what you propose.