應用於人類活動偵測之薄型雙頻貼片天線模組之設計

Abstract

本論文提出一種低剖面雙頻貼片天線模組，專為人體活動偵測應用所設計。 該模組可於兩個頻率頻段運作（6.25–6.75 GHz 與 7.75–8.25 GHz），提供雙頻功能，以提升偵測效能。最終設計整合一組三單元貼片天線陣列，並採用 L 形排列配置，同時實現雙頻操作與雙線性極化特性。天線陣列模組的整體尺寸為 25 mm × 25 mm，其中每個天線單元尺寸為 12.5 mm × 12.5 mm。本設計採用厚度為 0.38 mm 的 FR-4 基板，以實現其代表性的低剖面特性。 單一天線單元由一貼片結構構成，貼片上設有兩條彎曲狹縫，並透過導通孔（via）與共平面波導（CPW）饋線進行激發。雙頻響應分別由貼片本體與狹縫結構之輻射所產生。模擬結果顯示，所提出之天線模組在兩個目標頻段內皆具備高於 20% 的總效率，且呈現穩定且具單向性的正向（broadside）輻射場型。雖然實際製作之原型天線效率略有下降，但量測結果與模擬結果整體而言仍具有良好的一致性。

In this thesis, we propose a low-profile, dual-band patch antenna module designed specifically for human activity detection applications. The module operates across two frequency bands (6.25 - 6.75 GHz and 7.75 - 8.25 GHz), providing dual-band functionality that enhances detection capabilities. The final design incorporates a three-element patch antenna array arranged in an L-shaped configuration, achieving both dual-band operation and dual-linear polarization. The dimensions of the antenna array module are 25 mm×25 mm with each antenna element measuring 12.5 mm×12.5 mm. A 0.38 mm thick FR-4 substrate is utilized to achieve the design's signature low-profile characteristic. The individual antenna elements consist of a patch with two bent slits, fed by a via and a coplanar waveguide (CPW) feedline. The dual-band response is generated by radiation from the patch and the slits, respectively. In simulations, the proposed module exhibits a total efficiency greater than 20% and stable, unidirectional broadside radiation patterns within both target frequency bands. Although the efficiencies of the fabricated prototypes show slight degradation, the measured results align well with the simulated data.