5. Repeat the same procedure to draw the outer radius of the annular-ring. The circle should be centered at the origin and have a radius of 13.2 mm. Call this object opening.
3. We will let the aperture plane lie in the XY plane. Note that the axes shown in the upper left window are the X and Y-axes. Notice that after the mouse is clicked in the
the color of this object by clicking on the color button on the dialog box. Click on Enter
to create the closed and covered 2D-circle object.
Pick a color from this palette and click on the Execute.
will show zero value. Make sure the two entries are 0 and click on Enter. Since the
inner radius is 9.2-mm, we will draw this circle with a radius of 9.2-mm. Type a value
about the origin. Select LINES/CIRCLE. The modeler is now waiting for you to input
the center of the circle. Click your mouse at the origin. The XYZ coordinates column
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欢迎光临 EDA 教学网 Introduction:

We will create a model of a stripline fed annular-ring slot antenna. The objective will be to duplicate the results presented in the paper by C. Chen, et al, “Stripline-fed arbitrarily shaped printed-aperture antennas,” IEEE Trans. On Ant. And Propagat., Vol. 45, No. 7, July 1997, pp. 1186-1198, specifically the antenna described in Figure 11 of the paper. The stripline is spaced midway between the two ground layers and has a width of 2.6 mm. The ground layers are spaced 3.14 mm apart and the dielectric has an εr=2.2. The annularring slot on the upper ground plane has an inner radius of 9.2 mm and an outer radius of 13.2 mm. The stripline ends at the point directly below the center of the ring. In the paper data for this structure that was computed using the BEM (assuming infinite substrate and ground layers) is presented. Measured data is also presented, but details on the size of the actual ground/substrate layers of the experimental model were not given. The measured data had a resonance at 5.64 GHz. for this antenna. The |S11| was ≈ -25dB at that point. The computed data presented had a resonance at ≈ 5.59 GHz with |S11| ≈ -31.5dB.
2. First lets set the defaults. Go to OPTIONS/UNITS. Under the resulting menu you will be able to change the drawing units, the default is mm, which is what we will use here.
Training Workbook – Slot Antenna
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欢迎光临 EDA 教学网

欢迎光临 EDA 教学网
Conventixt refers to menu items (i.e. choose MODEL/MEASURE is an instruction to click on the Measure command under the Model menu)
segments, an angle of 10 gives 36,…). In this case 24 segments will produce a circle
segment every 15 degrees. Type the name inner_cir in the Name Box. You can change
欢迎光临 EDA 教学网

Ansoft HFSS Version 8 / 8.5 Training Workbook
Slot Antenna
EDA 教学网
Training Workbook – Slot Antenna
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• Bold Faced text is the text that is to be entered from the keyboard. • Italicized text will signify the names of buttons that you will click on
Training Workbook – Slot Antenna
Training Workbook – Slot Antenna
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欢迎光临 EDA 教学网 Sequence of Steps:

1. From the Maxwell Control Panel open the Project Manager. Create a new HFSS project titled Slot_ant. You should see the HFSS Executive Commands panel. Click on Draw… to enter the 3D modeler.
6. Next we will draw the 2D object that will become the top ground layer. Draw this object in the XY plane. Since the grounds and stripline are very thin compared to a wavelength we will make them 2D objects and can define them to be PEC (Perfect Electric Conductor) in the boundary setup. Select LINES/RECTANGLE. You will now have to enter the two corners of the rectangle. We can input the exact dimensions for the starting point of the rectangle directly in the X and Y boxes in the left-hand column.
Training Workbook – Slot Antenna
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欢迎光临 EDA 教学网

XY plane, the Z coordinate is unchecked and its value is frozen. This will keep all
The window in the upper left is the XY 2D drawing window. The lower left and lower right windows are two the YZ and XZ drawing windows, while the upper right window display a 3D-drawing window. All objects are drawn in the drawing windows. 2D and 3D objects can then be extruded, rotated, etc. to create more complex shapes. These shapes can then be unioned, subtracted, etc. to create the required model.