Conductor Backed Coplanar Wave Guide
The conductor backed coplanar waveguide with a ground via fence provides a lower EMI radiation compared to common microstrip lines or coplanar waveguides. But, compared to usual coplanar waveguides the values of phase constant and impedance can be changed as a result of the fence existence. Therefore, an electromagnetic simulation is essential to obtain these values. The simulation is performed with CST MICROWAVE STUDIO® and compared with measurements. Figure 1 shows a 3D view of the CST MWS model of the structure, which has a length of 88 mm. The system is excited by discrete ports at the beginning and at the end.
Figure 1: CST-MWS Model of CBCPW
In Figure 2 a more detailed view of the model is shown. The top view illustrates the ground plate and signal line metallisation, which is indicated by the grey color. The blue areas represent the substrate. Also, the via holes at both parts of the ground plane can be seen. The cross view shows, the connection of the vias.
Figure 2: Top view (left) and cross section of the structure.
The measurements have been performed by KAIST, Korea. A schematic drawing of the measurement setup is shown in Figure 3. The connector is modelled by a combination of the displayed capacitances and inductances.
Figure 3: Measurement setup.
Figure 4 shows a very good agreement of measurements and simulation results.
Figure 4: Measurement results (red) compared with results obtained with CST MWS (blue).
CST Article "Conductor Backed Coplanar Wave Guide"
last modified 2. Dec 2005 11:54
printed 3. Sep 2010 11:23, Article ID 106
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Article ID: 106
Last modified: 2. Dec 2005 11:54
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