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

Abstract

Due to the dielectric constant of traditional FR4 substrate is lower (ε 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 (Al 2 O 3 , ε r =9.8). Due to larger dielectric constant of Al 2 O 3 ceramic, the size of the designed patch antenna can be reduced to about 25mm × 32mm. It is found that the patch size and the length of transmission line will influence the return loss (S 11 ) 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 S 11 is −31dB. KEYWORDS: patch antenna, Al 2 O 3 , monopole antenna IntroductionIn the past years, the communication devices had been rapid developments in wireless local area network (WLAN) applications. To satisfy the 2.4GHz band of IEEE 802.11b and 5.2GHz band of IEEE 802.11a WLAN standards, dual operations in the 2.4GHz (2.4-2.484GHz) and 5.2GHz (5.15-5.35GHz) bands were demanded in practical WLAN applications. A small size antenna was highly desirable because the size of communication devices was decreased. The antenna should be designed in planar form to match the rapid development in wireless communication applications. For WLAN, the requirement of single-band antenna were also necessary for many applications, so printed monopole antennas with single-band operation were still in great demand [1].Recently, printed monopole antennas played an important role in wireless technology. The main reasons were low cost, small size, light weight, easy realization, and reasonably good performance, respectively [2]. Therefore, printed microstrip patch and slot antennas had the potential to meet the above requirements due to their inherently planar structures. There