A High-Gain Microstrip Patch Antenna Using Multiple Dielectric Superstrates for WLAN Applications

This paper presents the design and characterization of a microstrip patch antenna with multiple superstrates for performance enhancement operating at the central frequency of 5.5 GHz for high-gain WLAN applications. The performance of the antenna in terms of reflection loss and the gain are investigated using multiple high dielectric constant superstrates of Taconic CER-10 (epsilon(r)=10.2). Numerical results showed that the patch antenna has -10 dB impedance bandwidth of 2.54% which improves to 8.43% and 17.43% by employing a single and dual superstrate, respectively. The gain of the antenna increases from 6.1 dBi to 9.5 dBi using a single superstrate, which further enhances to 13.6 dBi by placing two optimized superstrates. Moreover, further increasing the number of superstrates did not significantly impact on the performance of the patch antenna. The final design of the antenna (patch antenna with two superstrates) is fabricated and measured. The measured results agree well with the simulated results. Due to the good impedance matching, high-gain and desired radiation patterns compared to the other superstrate antennas, this antenna is a good candidate for high-gain WLAN applications.