主動積體洩漏模天線

Abstract

一種微帶洩漏模天線由微帶線在基板的一面而單一平面電路在基板的 另一組成,洩漏的產生是激勵微帶線的第一高次(奇)模。而此一洩漏模則 是經由基板另一面的槽線利用電磁耦合激發。此一饋入設計為單一平面, 因此不需要貫穿孔,並且易於與主動電路連接。 當此一微帶洩漏模天線 置於一部份打開的波導時,成為一種準平面波導結構,理論分析根據嚴格的 格林阻抗積分方程式法,顯示此一新型準平面洩漏波天線,對其結構參數具 有寬頻可調範圍,對於微帶洩線的寬度變化則不顯著,量測的相對功率吸收 結果顯示可用頻率範圍與理論預測相符,量測的幅射場型亦與理論計算一 致。 利用主動積體洩漏模天線觀念設計的微波源模組的基本研究已實 現,此一新奇的天線模組利用微帶線做為輻射元件並採用單一平面技術設 計主動電路,量測的X-頻段傳輸型式注入鎖定主動積體天線源模組證實此 一設計適合線性陣列組合的準光學主功率合成,利用諧波平衡分析所提出 的主動積體天線顯示量測與分析的頻率與功率位準相符,同時量測與理論 的輻射場型亦相符。 A generic microstrip leaky-mode antenna is present. It consists of microstrip line on one side of substrate and uniplanar circuit on the other side. The leakage is producedby the excitation of the first higher-order (odd) microstrip mode coupledelectromagnetically through slotline on the opposite side of substrate. This feed designis uniplanar, which does not require via-holes and is easy to interface with active circuits. When the microstrip leaky-mode antenna placed in partially opened waveguide, itis a quasi-planar guiding structure. Theoretic results based on rigorous Green'simpedance integral equation method show that this new quasi-planar leaky- waveantenna has broadband tuning range via structure parameters, and is insensitive tomicrostrip line width variation. Measured relative power absorbed (RPA) resultsindicate that the useful frequency bandwidth agrees with what rigorous field theorypredicts. The measured antenna radiation patterns also agree very well withapproximate theoretic computations. A basic research carried out to design a microwave source module employing theconcept of an active integrated leaky-mode antenna. The novel active antenna sourcemodule utilizes microstrip as the radiating element while adopting uniplanartechnology for the active circuit design. The measured performance of an X-bandtransmission type injection-locked active integrated antenna source moduledemonstrated that such design approach was suitable for linear array integration forquasi-optical power combining. The harmonic balance (HB) analysis of the proposedactive integrated antenna agrees with the measurement in both free-running frequencyand power level. The measured radiation patterns of the active integrated antenna alsoagree well with the theoretical predictions.