The Study of Dual-band Metamaterial Radome and Multi-band Antenna

• Main Authors: HUANG, HONG-SHENG, 黃鴻昇
• Other Authors: SU, HSIN-LUNG
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/3363dt

碩士 === 國立屏東大學 === 資訊工程學系碩士班 === 105 === This thesis proposes a dual-band circularly polarized metamaterial radome for antenna gain enhancement, and two multiband antennas are able to apply in mobile devices. One is for smart watch and the other is for tablet computer of the metal casing. This dual-band metamaterial radome improves the gain of circularly polarized antenna. The refractive index of the metaterial was designed to less than one. This feature can use to focus on the electromagnetic wave and increase the gain of antenna. This dual-band metamaterial is placed in front of the circularly polarized antenna 8 mm. The antenna gain increases highest 1.47 dB and 2.78 dB at the 2.4 GHz and 5 GHz band respectively. These first proposed multiband antennas are for the smart watch applications, the size of the smart watch is 49 mm × 35 mm × 5 mm. They are placed in the top side and bottom side of the smart watch and printed on a 0.4-mm thick FR-4 substrate. The clearance area both of the top side and bottom side are 2 mm × 35 mm × 5 mm. These antennas cover GPS, GSM1800, Bluetooth and Wi-Fi bands. Their isolation and efficiency are more 12 dB and 34% in the operated bands. These proposed second MIMO antennas are for the metal-casing tablet computer applications. The size of the metal casing is 170 mm × 240 mm × 0.8 mm such as the 10-inch tablet computer. These MIMO antennas includes two SISO antennas. These two SISO antenna are placed in the upper left and lower right corner of the metal casing. The SISO antennas is composed of two open-slot. One is L-type open-slot of 62 mm length, the other is open-slot of 25 mm length, and their width are 2 mm. Finally, these MIMO antennas can operate at the LTE and the WWAN bands. The antenna efficiency is about 33.5－53.8% in the lower bands of LTE and WWAN; it is about 45.5－78% in the middle and high bands of LTE and WWAN. The transmission coefficients of these MIMO antennas are less than -15 dB and ECC is less than 0.11 in LTE and WWAN bands.