UHF頻段平面式天線電路設計及混合式火箭通訊模組研製

Design of Planar Antenna System and RF Module of Hybrid Rocket in UHF Band

蔡邦均(Pang-Chun Tsai)

指導教授 ： 林信標 ； 林丁丙

國立臺北科技大學/電資學院/電腦與通訊研究所/博士(2014年)

摘要

本論文主要針對在UHF頻段下之消費型電子產品的天線與RF元件之縮小化設計，以及混合式火箭的RF模組電路設計。在天線設計的部份，主要提出多模態和多頻段之天線。其中多模態天線可應用在全球數位電視廣播接收頻段（470-862 MHz）之微型化天線，利用在微帶線的接地面做螺旋開槽，使微帶線的返回電流路徑延長而達到低頻共振效果。在接地面設計七個共振路徑，激發多個諧振頻率達到寬頻的效果。利用開路的微帶線來激發天線的多模態，並且加入矩形金屬貼片來達到阻抗匹配的效果，使天線輻射場型具有全向性接收的優點。而多頻段之天線主要採用平面式倒F形天線設計，且含蓋七個手機通訊頻帶GSM-850 (824-894 MHz)、GSM-900 (880-960 MHz)、DCS-1800 (1710-1880 MHz)、PCS-1900 (1850-1990 MHz)、UMTS (1920-2170 MHz)、GPS (1575.42±5 MHz)和IEEE 802.11 (2400-2484 MHz)。此天線主要將接地路徑延伸拉長使激發出低頻諧振頻率，並且在饋入路徑與接地路徑間加入一個間隙。此間隙可做其他諧振頻率之阻抗匹配元件，並結合多路徑的諧振頻率達到多頻段之諧振與天線縮小化之機制。
其次，在RF元件的部份，提出1×4波束切換之智慧型電路。此電路採用所提出的π型等效微帶線理論，設計出縮小化之π型等效枝幹耦合器與45°相移器等元件。並且透過微控制器建立四組不同電路路徑之相位模式±45°和±135°，產生四組不同方向之波束型式。可降低其它方向之干擾源，進而提升室內LTE收訊能力。
最後，針對在混合式火箭與地面接收站之遠距通訊，而提出RF模組之電路設計。為了大量減輕整體火箭之重量，火箭外殼將採用FRP材料為基底，因此將在FRP材料上設計共平面之環繞型天線，其操作頻率為433 MHz。此天線架構主要採用三片金屬貼片且呈共平面的形式，中間金屬貼片為天線主要輻射體，其共振長度為半波長。搭配高接收靈敏度之通訊模組，以及高功率之功率放大器。以提昇在混合式火箭與地面接收站之通訊範圍，使地面接收站能有效追蹤定位混合式火箭之位置。

關鍵字

螺旋天線 ； 平面式倒F形天線 ； 波束切換電路 ； 混合式火箭

並列摘要

In this dissertation, in order to sufficiently utilizing the UHF band for both mobile, digital broadcasting, and space communications scenarios, we proposed not only the design of miniaturized antennas and 1×4 switched-beam smart circuit for usage of consumer devices, but also the RF module of hybrid rocket.
Firstly, a novel multimode miniaturized antenna is proposed for operation in the digital television (DTV) reception band (470-862 MHz) throughout the world. To achieve broadband characteristics, the proposed spiral antenna is constructed using seven resonance paths in the ground plane. The impedance matching and bandwidth of the spiral antenna are significantly affected by the sheet metal on the signal line. The antenna is able to realize an omnidirectional radiation pattern for the entire frequency band.
Regarding the need of multi-band for mobile communications, the second study applied printed inverted-F monopole antenna to design the 7-frequency band to cover from GSM-850 (824-894 MHz), GSM-900 (880-960 MHz), DCS-1800 (1710-1880 MHz), PCS-1900 (1850-1990 MHz), UMTS (1920-2170 MHz), GPS (1575.42±5 MHz), to IEEE 802.11 (2400-2484 MHz). With printed inverted-F monopole antenna, a gap between the fed and the ground path was added and the ground path was extended to excite the low-frequency resonant frequencies as well as combine with multi-path resonant frequencies to achieve multi-frequency resonances.
Next, the 1×4 switched-beam smart circuit is presented, which is composed by a miniaturized branch-line coupler and a miniaturized 45° phase shifters based on the newly proposed π-equivalent microstrip lines. The miniaturized 1×4 switched-beam smart circuit can create four phase modes ±45° and ±135° for the circuit path through a microcontroller. Four generated beams can reduce the interference from other directions to enhance indoor LTE communication.
The final topic aims to implement the telematics between hybrid rockets and the ground receiving station. In order to largely reduce the rocket weight, Fiber-Reinforced Plastic (FRP) is utilized for the hybrid rocket casing, on which coplanar wraparound antennas with the operation frequency 433 MHz are designed. The antenna structure contains three coplanar printed patches, in which the middle printed patch is the primary radiator and the resonant length appears half-wavelength. The RF module with high receiver sensitivity and high-power power amplifier are included to enhance the communication coverage of hybrid rockets and the ground receiving station so that the ground receiving station could effectively tracking the hybrid rocket.

並列關鍵字

Spiral antenna ； Printed inverted-F monopole antenna ； Switched-beam circuit ； Hybrid rocket

參考文獻

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