12 平面轉接器分析.doc

附件一：報告撰寫格式及樣本1.2平面轉接器分析主持人：陳俊雄國立台灣大學電機系共同主持人：XXX （單位）參與研究人員：XXX, XXX,...摘要本文介紹卓越計畫報告的參考撰寫格式首先在第一頁內標明分項計畫工作項目（或子項目）的題目及參與人員，並撰寫中文摘要，中文部分請以一頁為原則， 接著在第二頁起以英文方式描述該項目的報告內容，除Title、Authors及AbstractConclusions^ 與 References 等部份外,正文略含 Introductions Theory、Results^字體中文為標楷體，英文為Times News Roman ,大小除工作項目名稱取2（）pt ,作者取14仇,其餘正文均取12氏,標題則以粗體大寫強調之 文書系統請使用MicrosoftWord ,最後並應提供印出紙版及電腦檔案版面設定為上下左右各留3cm，紙張大小為A4 ,頁次標示在頁尾中，標法請依分項計畫各工作項目（或子項目）■頁次格 式,如1.2 - 1, 1.2 -2(或1.2.1丄121・2)等段落方面取2倍行高(Double space), 段與段區不必再留額外空白圖表，下接其說明，但可置於文中或文後。

印出的 結果可參考底下所列印出的形式頁數各工作項目(或子項目)以1()頁為原則1.2 Analysis ofPlanar TransitionsChun-Hsiung Chen, Yo-Shen Lin, and Chih-Wai KaoABSTRACTNovel uniplanar 180 hybrid-ring couplers consisting of coplanar-waveguide (CPW) rings and spiral-type phase inverters are proposed. In this study, CPW phase inverters with single-spiral and twin-spiral type slot line short stubs are utilized to design the hybrid-ring couplers. Specifically, two hybrid-ring couplers with 33% (single-spiral type) and 40% (twin-spiral type) bandwidths are implemented and examined, theoretically and experimentally.Keywords - Spiral-type phase inverter, 180 hybrid-ring coupler.INTRODUCTIONHybrid-ring couplers are fundamental components of microwave circuits such as balanced mixers, phase shifters, and feed networks in antenna arrays. The rat-race hybrid-ring coupler is the most common one, but its area is undesirably large and its bandwidth is also limited due to the use of a 32 /4 line segment.In recent years, uniplanar transmission lines such as coplanar waveguide(CPW), slotline, and coplanar stripline are widely used in micro wave integrated circuit(MIC) and monolithic microwave integrated circuit(MMIC). Uniplanar lines have the merits such as easy realization of short-circuit end, no need for via holes, low dispersion, andstructures, several 180 hybrid-ring couplers have been reported [1 J-[3J. In those papers, suitable wideband open circuits have been properly incorporated in the hybrid design, since the bandwidth of a hybrid is mainly determined by the performance of these open circuits. The simplest open circuit structure is the qu art er-wave length short-circuit stub, but its bandwidth is quite limited. To improve the bandwidth, some modified structures have been proposed, such as to use the twin short stubs or radial stubs [4]-[5], but their sizes are still large.Recently, a twin-spiral slotline short-stub structure was proposed to reduce the size of CPW-to-slotline transition [6]. Based on the same idea, novel 180 hybrid-ring couplers with single-spiral and twin-spiral type phase inverters are proposed and carefully examined. These hybrid-ring couplers may achieve the goal of small size and good bandwidth, thus, may find applications in MIC and MMIC.SPIRAL-TYPE UNIPLANAR PHASE INVERTERSReverse phase along a CPW line can be achieved by using either one of the uniplanar (CPW) phase inverters as shown in Fig. 1. In these phase inverters, the signal strip of left CPW is connected to the ground planes of right CPW and the signal strip of right CPW is connected to the ground planes of left CPW by two bond wires. Here, an open circuit at the CPW crossover region is realized by using either the single-spiral or twin-spiral type slotline short stub, which is the modified version of the conventional 2/4 short-stub structure. The single-spiral type phase inverter (Fig. 1(a)) has the advantages of small size and low radiation loss but its bandwidth is relatively limited. To improve the bandwidth and also to keep the size small, the twin A /4 short-stub5structure is modified [6] to form the twin-spiral type uniplanar phase inverter as shown in Fig. 1(b). Since the twin-spiral section is symmetric and is fed by a slotline, the two half parts of the twin-spiral section are excited with a 180 phase difference. To compensate the effect of slotline bend, the length of spiral-like stub should be slightly longer.In this study, both single-spiral and twin-spiral type CPW phase inverters are fabricated on the FR4 substrate ( e r =4.3, tan d =0.022, thickness h = 1.6mm). They are measured by the HP8510B network analyzer together with the TRL (through-refleet-line) calibration technique. Theoretically they are also simulated by the IE3D software, which is based upon an integral-equation and method-of-moment algorithm. Fig. 2 shows the measured results for both single-spiral and twin-spiral type phase inverters. The corresponding simulated results are in good agreement with the measured ones and are not shown in Fig. 2. The bandwidth of twin-spiral type phase inverter is greater than that of single-spiral type phase inverter, as expected・Fig. 2 also compares the normalized power losses of single-spiral and twin-spiral c atype phase inverters. They are calculated by the equation 1- I SH h - 1521 h - The normalized power loss of single-spiral type inverter is lower than that of twi。