Abstract: Considering the disadvantage of the traditional planar inverted-F antenna (PIFA), a miniaturization PIFA applied in the wireless local area network (WLAN) wireless router was proposed. The dimension of the antenna and PCB, the antennas placement on the PCB and parameters of the plastic shell were investigated to improve the performance. Due to the small size and simple feed structure, the proposed antenna can be feasibly integrated on the PCB. The measured results show that a bandwidth between 235 GHz and 25 GHz with return loss less than －10 dB can be achieved. Meanwhile, the radiation beam width of this antenna is much wider than that of the traditional PIFA. The nearly isotropic radiation patterns guarantee the reception of signals in all directions.

Key words: planar inverted-F antenna (PIFA), miniaturization, broad beam, wireless local area network （WLAN）