Fabricate wide-band microstrip line T-shaped antenna on the Al2O3 substrate

Recently, due to the rapid developments in the wireless communications, low cost, small size (low profile) and easy fabrication are the major goals of the wireless communication devices. In this paper, the resonant frequency of the purposed antenna is 5.77 GHz, which could be applied for the use of IEEE802.11a WLAN (5725 MHz-5825 MHz) and RFID. However, Al2O3 ceramic is adopted to be the substrates of the antenna in this research because of its high dielectric constant (epsilon(r)=9.8). Therefore, the size of the purposed antenna will be reduced. In this paper, the optimum microwave characteristics of the purposed antenna are: small size (14.18 min x 20 mm), wide bandwidth (560 MHz/9.71 %) at the resonant frequency of 5.77 GHz, and high return loss S-11 of -40.92 dB, and enough gain of 2.8 dBi for real use. For that the fabricated antennas can be used in the microwave communication circuits.