_{PIFA Basics}

Our Planar Inverted F Antenna (PIFA / GSM PIFA) consists of a rectangular planar element located above a ground plane, a short circuiting plate, and a feeding mechanism for the planar element.

The GSM PIFA antenna is a variant of the monopole where the top section has been folded down so as to be parallel with the ground plane. This is done to reduce the height of the antenna, while maintaining a resonant trace length. This parallel section introduces capacitance to the input impedance of the antenna, which is compensated by implementing a short-circuit stub. The stub’s end is connected to the ground plane via the short-circuiting plate on the edge of the antenna, whose function is to extend the bandwidth of the GSM PIFA.