Planar inverted-F (PIFA)

Image of the Planar inverted-F (PIFA).

The PIFA can be considered as a kind of linear inverted-F antenna with the wire radiator element replaced by a plate to expand the bandwidth. It can also be considered as a kind of short-circuited microstrip antenna (short-circuit MSA). [Hirasawa, K., Haneishi, M]

When the width of the short-circuit plate is set narrower than that of the planar element, the effective inductance of the antenna element increases, and the resonant frequency becomes lower than that of a conventional short-circuit MSA having the same sized planar element. So, the PIFA is an antenna having its structure situated between that of the transmission-line antenna with the wire element and that of the short-circuit MSA. [Hirasawa, K., Haneishi, M]