Numericlal study of a PIFA mounted on a car compared to measurements

The influence of a car structure on the radiation pattern from a dual band planar inverted F-antenna (PIFA) resonant in the 900 and 1800 mobile communication bands has been studied. Numerical simulations using FDTD, FIT and a combination of FEM-FDTD have been used for analyzing the PIFA mounted on a car as well as mounted on infinite and finite sized ground planes. The computed return loss and gain patterns have been compared with measurements for a fabricated PIFA. The results show that the car structure has a large impact on the gain pattern. The achieved agreement between computed and measured gain shows that FIIM-FDTD and FIT programs are suitable for analyzing small and complicated antennas placed on much larger structures, such as a car.