Design Small-Size and Wide-Band T-Shaped Patch Antenna on Ceramic Substrate

Due to the dielectric constant of traditional FR4 substrate is lower (epsiv_r=4.2); it is not suitable for the fabrication of small size microwave antennas. In order to reduce the size of the fabricated antennas, the ceramics with higher dielectric constant can be used as the substrates of the designed patch antenna. In this paper, the designed patch antenna is printed on aluminum oxide (Al₂O₃, epsiv_r=9.8). Due to larger dielectric constant of Al₂O₃ ceramic, the size of the designed patch antenna can be reduced to about 25mm times 32mm. It is found that the patch size and the length of transmission line will influence the return loss (S₁₁) and the resonant frequency of the fabricated patch antennas. The optimum bandwidth of the designed antenna can reach 400MHz/16.3%, the resonance frequency is near 2.45GHz, and the S₁₁ is -31dB.