使用一新式半重入型耦合結構設計寬頻三分貝微帶方向耦合器

Abstract

摘要 在本論文中,我們探討一個新式的半重入型結構的微帶方向耦合器.這個新的耦合結構是一個簡單組成,且可以在微波積體電路的設計上實現緊密的耦合(三分貝或更高的耦合)效應.在論文中我們將使用商用的CAD軟體來取代全波的數值分析,並且用來計算這個耦合器相依於頻率的特性.而由CAD軟體所模擬出的數據將與實作電路的量測值做比較.傳統的寬頻三分貝微帶方向耦合器的設計,大多是採用Lange結構來加以實現.如今我們將使用新的半重入型耦合結構來取代它,而且可以得到較佳的表現.這個新的耦合結構結合了傳統的半重入型結構與微帶槽線式耦合器二種結構.它少去了Lange結構連結線的使用且同時提高了設計時的自由度, 所以自然提升了製造的良率和降低生產時的成本.在本文最後我們將配合多節耦合的結構來實現一寬頻的三分貝微帶方向耦合器.

Abstract A new type of microstrip semi-reentrant mode directional coupler has been proposed. This proposed coupler is simple to construct and capable of realizing tight coupling (3 dB or higher) in microwave integrated circuits (MIC) with high directivity. In this thesis, the commercially available CAD software packages (IE3D) is applied to calculate frequency-dependent characteristics of these couplers and compare the measured responses. Traditionally, the design of 3 dB wide- band coupler on microstrip has been accomplished by the well-known Lange coupler. The new semi-reentrant coupler could replace the Lange section and is shown to have superior performance. This new configuration combines conventional semi-reentrant and strip-slot coupler which offers additional design freedom and requires no tuning, or bonding, thus providing higher yield and lower manufacturing cost. Finally, an experiential wideband 3-dB directional coupler has been shown and constructed by the multi-section structure in this thesis.