- 學位論文
物聯網裝置之多頻段天線設計
Design of Multi-Band Antenna for Internet of Things(IoT) Devices
摘要
對無人機而言能夠即時且穩定將大量的數據資料回傳至地面接收站有著迫切的需求。但往往在傳輸時無法同時兼顧傳輸距離、傳輸速率以及通訊的穩定性，若是只採用單一的通訊協定，則需要在頻段上面的選擇進行取捨。同時因為無人機在不同的場景有不同的用途，現在需要越來越小的無人機機身，要如何將上面的各種模組縮減尺寸或是最大程度利用空間也成為需要解決的問題。 本文使用折疊偶極天線 ( Folded Dipole Antenna ) 為設計原型作為參考並加以設計，天線的尺寸為 101 mm × 25mm × 9mm，支援的頻段包括LoRa ( Long Range ) 850 MHz - 930MHz 以及 WiFi 2.4GHz、5G NR ( n77, n78, n79 ) 頻段，其中本設計採用LoRa的頻段為無許可頻段 860MHz - 930MHz ，這個頻段為免費頻段，無需申請即可使用。本文也將天線結構做成立體中空的設計，並安裝在四軸無人機的機臂上能夠讓機身的空間不受天線大小以及擺放的限制，組成 MIMO 系統也可以彌補在接收以及發射時的訊號死角。同時將天線結構包覆在機臂上可以很大程度的減少無人機在飛行中時的風阻，也可以讓天線在無人機的空間得到更好的運用，本文的設計使得無人機在 LoRa、WiFi以及5G NR 頻段的使用場景更具有實用性。
並列摘要
There is an urgent need for UAVs to be able to instantly and stably transmit large amounts of data back to ground receiving stations. However, it is often impossible to take into account the transmission distance, transmission rate and communication stability at the same time in the transmission, if only a single communication protocol is used, it is necessary to choose the frequency band. At the same time, because the UAV has different uses in different scenes, and now the UAV body needs to be smaller and smaller, how to reduce the size of the above various modules or maximize the use of space has become a problem that needs to be solved. In this paper, Folded Dipole Antenna is used as a reference for the prototype design. The antenna size is 101 mm × 25mm × 9mm. Supported frequency bands include LoRa (Long Range) 850 MHz - 930MHz, WiFi 2.4GHz, 5G NR (n77, n78, n79) bands, Among them, the frequency band of LoRa adopted in this design is the unlicensed frequency band 860MHz-930MHz, which is a free frequency band and can be used without application. In this paper, the antenna structure is also made into a three-dimensional hollow design, and installed on the arm of the four-axis UAV, so that the space of the fuselage is not limited by the size and placement of the antenna, and the composition of the MIMO system can also make up for the dead Angle of the signal when receiving and transmitting. At the same time, the antenna structure wrapped on the arm can greatly reduce the wind resistance of the UAV in flight, and also make the antenna better used in the space of the UAV. The design of this paper makes the UAV more practical in the use of LoRa, WiFi and 5G NR frequency bands.