Kicad 2.4Ghz Antenna Design

In some of our designs we need a  2.4Ghz PCB antenna. We had to use a few tricks to get the design working in kicad, here is how we did it:

1- Select the design

After reviewing a few designs that I found on the web, I decided to use the Texas Instruments AN043 2.4Ghz antenna.

2- Create the component:

Simply open up the component editor and create an antenna with 2 pins, the signal pin and a ground pin that is configured as a bidirectional pin.

Here it is in the schematic.

3- Create the footprint

Open up the footprint editor, create all the antenna legs as multiple pin1 SMT padsand  place them so they are touching each other as shown in the application note. Since this is a RF design, the ground leg touches the signal leds. This will create error in the PCB layout when the footprint is used. The software sees the signal net touching the ground and will throw an error. To avoid this I incorporated a 0 ohm resistor footprint into the ground led design. As can be seen in the footprint editor picture, PAD 2 is seperate from the ground leg pad 1. Also there are 2 pad 1, the smaller is the second pad for the resistor.

The 2 resistor pads have 0 in the Solder mask clerance while the other antenna pads have -2 mm (-1mm also works) to fool the software into covering the antenna pads with the solder mask.

As you can see with a gerber viewer, the solder mask covers the antenna but not the component pads as intended.

Here you can see what the layout looks like.

All our Kicad footprints and designs will be available after our Kickstarter campain is over.