How to feed a microstrip patch antenna with an SMA connector on a finite ground

This article is a practical guide on how to feed a microstrip patch antenna on a finite ground using a waveguide source.

As an example, we will look at a microstrip circular patch antenna with a feed line connected by an SMA connector to a coaxial cable.


The front and side (section) view of the physical microstrip patch antenna for illustration purposes. Dimensions not to scale.


The circular patch antenna is modelled using a finite ground plane. Instead of using an approximation of the feeding mechanism (for example, a pin feed or edge feed), an SMA connector will be modelled as in the physical model. A waveguide port and waveguide source are added to the front face of the SMA connector to excite the patch antenna.


An example of a circular patch antenna on a finite substrate with a feed line at the bottom of the substrate in CADFEKO.

Left: 100% opacity; Right: 20% opacity.


To model the SMA connector:


Note: Confirm that the regions and faces of the connector have the correct material properties after the union operation.



 A model of a SMA connector was imported as a .cfx file and placed near the end of the feed line. Opacity set to 20%.


To excite the microstrip antenna:


The face of the SMA connector is selected.



A waveguide port is added to the selected face.




A waveguide source is added to the waveguide port.


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