The Design and Implementation of An Ultra-Wideband Antenna with 5.1-6 GHz Band Stop

• Main Authors: Wei Fan Wu, 吳韋汎
• Other Authors: Chu Yu Chen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/84888023924242576372

碩士 === 國立臺南大學 === 電機工程學系碩博士班 === 104 === An ultra-wideband antenna with a band notch has been proposed. Based on the stepped impedance concept, a 3.4-17.9GHz UWB monopole antenna with FBW ratio of 136.1% is firstly developed. To prohibit interference from the WLAN (5.15-5.825GHz), a square slot in the radiation metal sheet is employed to provide the specific notch. The resonant frequency of such a notch can be controlled by adjusting length and width of the slot. Finally, it produces a 5.05-6GHz transmission rejection band with center frequency of 5.5GHz in the original ultra-wideband antenna. In addition to suppress unwanted transmission band, an electromagnetic coupling parasitic square patch is added on the back of the radiating metal. It not only provides another resonance frequency but also effectively improves impedance matching without affecting the original resonant frequency and band notch. The overall size of the designed antenna is 1.99λg×1.49λg. Besides, both reflector element and director element are integrated with the radiating antenna, which is called a microstrip quasi Yagi monopole antenna. This antenna can enhance the concentration of beam and form an antenna with high directivity gain. The bandwidth of directional antenna is 3.6GHz-6.1GHz and its bandwidth ratio is 51.5%. The size of antenna is 4.72λg × 2.16λg. Finally, the three proposed antennas are simulated using Ansoft HFSS electromagnetic software and fabricated on the FR4 substrate with thickness of 0.8mm, relative permittivity of 4.4, and loss tangent of 0.02.