Reduced microstrip slot multiband antenna with A U-shaped resonator for wlan applications

The development of two reduced microstrip slot antennas with a U-shaped resonant configuration is presented. The additional resonator is located inside the slot and is designed to perform dual band operation, covering the 2.4 GHz and 5.8 GHz WLAN frequency bands. The main goal of the antenna design is to get the optimum size reduction without significant degradation of electrical characteristics compared to a similar antenna reported in literature. The antenna implementation was done using low cost substrates. A size reduction of 84% was got by using a dielectric constant substrate of 10. Simulation and experimental results are presented for both antennas, showing close convergence. Their radiation patterns have quasi-omnidirectional behavior useful for WLAN applications. Both antennas have small size suitable for mobile applications.