In this tutorial we will construct a horn antenna for the Wi-Fi band at 2.45 GHz from a sheet of brass. All fabrication steps are explained and measurement results are provided in the last step. The results from a 3D electromagnetic simulation, such the Gain or the Radiation Pattern of this antenna are available here : http://kavea.free.fr
Step 1: Tools and Materials
To build this antenna you will need:
- 1 mm thick sheet of brass or copper
- SMA connector
- 1 mm diameter copper wire
- soldering iron (min 50 W)
- dremel or something similar to cut the sheet
Step 2: Cutting the Sheet of Brass
In this step you will have to cut out 7 parts of the antenna from a sheet of brass. To do this, use a dremel or similar grinding tool. As usually, pay attention on protection of your eyes and the face since grinding discs can brake. Dimensions (in mm) of each part is visible on the photo.
Step 3: Soldering
To solder obtained parts you should have a good soldering iron or better a soldering station with a power of 50 W or more. Use a point soldering at the beginning in order to slightly join all parts together. When it's done you can solder all joints.
Step 4: Adding an Excitation Monopole
In the last step you will need to build a small monopole. To do this solder an SMA connector to a copper wire in order to get a whole length of 3 cm (see photo, but pay attention on the optical effect, the length is exactly 3 cm !).Then drill a hole of 6 mm diameter 31 mm away from the rear part of the horn (see photo), then solder the monopole.
Step 5: Measurements
Here we provide measurement results for the SWR and the S11 parameter. As we can see from the photo, obtained antenna have a bandwidth (@ SWR=2) between 2.34 GHz and 2.62 GHz.