New App Note: Planar Inverted-F Antennas (PIFA)

AUSTIN, TX – Abracon, LLC (Abracon), an industry leader in providing frequency control & timing, RF & antenna, and inductor & connectivity component solutions, announces the release of a new application note titled “Planar Inverted-F Antennas (PIFA),” written by Antti Silventoinen, Sales Manager at Abracon.

Please read the excerpt below:

"Today, wireless connectivity for all sorts of electronic devices has become increasingly important. As a result, the demand for components used for wireless communication has grown significantly, among them antennas. This technical note will provide information on one commonly used antenna type, called Planar Inverted-F Antennas (usually abbreviated PIFAs) with the purpose of highlighting the pros and cons of PIFAs in different applications.

The PIFA is a sort of special case of the monopole antenna. It originates from the inverted-F antenna, which is basically a monopole parallel to the PCB, with a short circuit arm implemented. The PIFA is an evolution of this antenna type, with a top plate instead of a single wire.

PIFAs, like patch antennas, are inherently narrow banded. The difference is, with PIFAs the bandwidth can be widened, using different methods, such as slots in the plate and parasitic GND elements. Also, the size of the top plate can be changed by these methods, and thus smaller antennas can be created. Another way of modifying the size of the PIFA itself is by using so-called top loads, although not without consequences. By adding small capacitances to the far end of the antenna lower frequencies can be reached. Doing so will worsen the radiation capabilities but can be used to achieve the best balance between size and performance for a certain application.

One of the biggest advantages of PIFAs is the limited space required on the electronics board. Since the antenna is positioned above and parallel to the PCB, the only required space is where the mounting pins are positioned. No clearance toward the ground or other metal is needed, which means it is possible to mount components underneath the antenna, on both layers of the PCB."

Click here to read the full application note.