Is that a loading coil antenna

[ofosot69]

I came across one WiFi receiver of my wireless keyboard and after opening the USB receiver, I saw a strange looking printed antenna on the PCB.

It's like a series of square waves printed on the PCB.

Is that a loading coil antenna or something else?

I have attached the snapshot of the PCB.

 

[jwt873]

A loading coil is generally a component that you would attach to a whip or wire antenna in order to match impedance..

In this case, the zig zag trace is the whole antenna. At UHF frequencies the wavelengths are so short, they can use PC board traces as the antenna.

Here's a short primer on the various types of circuit board antennas. Designing Effective PCB Antennas for Wireless Communication Systems

 

[Ubbe]

That wider copper foil to the left are ground and then you tap the signal a bit higher up and then it's a bigger gap until the actual antenna part starts. So yes, it is a sort of a loading coil to do a impedance match.

/Ubbe