 The inverted @-@ F antenna was first conceived in the 1950s as a bent @-@ wire antenna . However , its most widespread use is as a planar inverted @-@ F antenna ( PIFA ) in mobile wireless devices for its space saving properties . PIFAs can be printed using the microstrip format , a widely used technology that allows printed RF components to be manufactured as part of the same printed circuit board used to mount other components . 
