Patch Antenna

Patch Antenna



Operating frequency = 4.52 GHz.


Patch dimensions :

Length = 2 cm

Width / Length = 1.5


Feed probe :

x = Length / 4

y = Width / 2

radius = 0.1 mm


Substrate :

permittivity = 2.2

thickness = 0.1524 cm



View of the final geometry :



This geometry contains only simple objects and should be easily designed with GiD. However, there is something important to notice : the metal patch can not be simply created over the dielectric substrate. This would lead to a mesh with a doubled meshed patch (triangles from the patch itself and triangles from the underlying substrate). To create properly the junction patch/substrate, the surface of the substrate must be holed with Geometry=>Edit=>Hole NURBS surface. Select the upper surface of the substrate and create an hole with the contour lines of the patch.


Assign the dielectric property to the substrate (follow the example of the dielectric lens).


The properties of the patch and ground plane (lower surface of the substrate) are slightly different. Indeed, the surface must be PC (perfect conductor) instead of dielectric :



Since the wire representing the feed is inside the substrate, note that it is necessary to change the medium surrounding this wire :




As most patch antenna, this one is very thin. Its thickness is about λ/40. To correctly simulate this thickness, a fine mesh size should be used. In the following options window, 40 elements per wavelength were selected in order to achieve the required mesh quality :




For the following results, the operating frequency is 4.52 GHz.


Electric currents visualization :




Magnetic currents visualization :




3D Far field pattern :




The input impedance is usually computed on a range of frequency, in order to find the best operating frequency :




The file named Zin_VSWR.txt in the project folder contains the complex value of the input impedance for each computed operating frequency. The real part is named R(Zin). The imaginary part is named I(Zin). The following picture shows the result (curves displayed with a third party software) :



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