Design and characterization of a low profile miniaturized UHF PIFA for compact wireless sensor nodes

In this work, a miniaturized planar inverted-F antenna (PIFA) with low profile on a small ground plane is designed and characterized for integration in a compact autarkic wireless sensor node. The physical size of the antenna is 24 mm × 11 mm × 3 mm (0.07λ × 0.03λ × 0.01λ) including the small ground plane and operates in the UHF band at 868 MHz with a -10 dB impedance bandwidth of 9 MHz. The antenna gain is -12 dBi. The resonance frequency and input impedance can be easily tuned by altering the meander length and shorting post position, respectively. Simulation and measurement results are presented.