Miniaturization of Differentially-Driven Microstrip Planar Inverted F Antenna

The modification of a conventional single-ended microstrip planar inverted F antenna (SE-PIFA) into a novel differentially-driven microstrip planar inverted F antenna (DD-PIFA) and the comparison of their performances are first made. It will be shown that the DD-PIFA provides better performance than the SE-PIFA does. Then, the frequency trimming and more importantly the miniaturization of the DD-PIFA are described. A simple formula for determining the resonant frequency of a DD-PIFA is given. Calculated, simulated, and measured results at 2.45 GHz are discussed, indicating the potential applications of the DD-PIFA in high-level integration of radio transceivers for wireless communication systems.