In this paper, a planar inverted-F antenna (PIFA) for LoRaWan network is studied. The proposed structure covers the 868MHz radio frequency band used by LoRaWan in Europe and the 915 MHz radio frequency band used in North America. The miniaturization in the antenna size is achieved by introducing a meandered microstrip line. The setup of the meandered line allows obtaining lower resonant frequency and large -6dB bandwidth and important gain. The antenna has compact size of 40x26x1.6mm3. The radiation patterns in the operating bandwidth are almost the same as the omnidirectional characteristics. The influences of various design parameters are investigated using CADFEKO, a Method of Moment (MoM) based solver.