微型化低損耗電感及變壓器之設計與應用

Abstract

本論文介紹新研發之微型化高品質因數電感以及微型化高耦合係數之堆疊式變壓器，並將此電感及變壓器應用在24GHz汽車防撞雷達系統中之低雜訊放大器和傳送接收切換器電路中，論文中所有晶片皆使用CMOS 0.18μm製程製作。 第一部分，利用contact將CMOS 0.18μm製程當中較薄的下層金屬(Metal 1~5)每兩層打穿並聯的方式來增加金屬厚度，並利用此種並聯的金屬走線來製作立體電感，藉此大量提升立體電感的品質因數，同時得到縮減電感面積的好處。接著進一步利用將金屬透過contact打穿並聯的方式來設計堆疊式變壓器。堆疊式變壓器的第一級電感和第二及電感都使用此種方式來製作，藉此減少訊號經過電感時所產生的損號，此外堆疊式變壓器上下寬邊耦合的結構可以幫助產生較高的耦合量，綜合以上兩種原因可以使得此種新型堆疊式變壓器的傳輸損耗變小。 第二部份，我們實際將新式立體電感應用在24GHz低雜訊放大器以及傳送接收切換器的設計上，透過量測結果可以證實此種電感的實用性，此種新式電感可以有效幫助縮減電路面積，同時由於其品質因數較過去傳統平面電感還良好的關係，所以可以進一部幫助增進電路性能。 第三部分，我們利用新型堆疊式變壓器來設計24GHz低雜訊放大器以及傳送接收切換器，透過變壓器耦合訊號的原理將電路中原本會因為元件非理想效應產生的流失訊號再次耦合到能夠被有效利用的路徑，藉此減少電路的訊號浪費，並且提升電路性能，由於新型堆疊式變壓器的面積也比過去傳統平面式變壓器微小許多，因此也能有效幫助縮減電路面積。

This study introduces new developed miniaturized high quality factor inductors and miniaturized high coupling coefficient stacked transformers. Then the inductors and transformers are applied in low noise amplifier and T/R switch in 24GHz automotive anti-collision radar system. All chips in this thesis are manufactured using CMOS 0.18μmprocess. At the first part, a method which uses contacts to connect the thin metals (metal1~5) of CMOS 0.18μmprocess in order to thicken the metal thickness is used to manufacture 3D inductors. With the method, the quality factor of the inductor is increased and the size is shrunk at the same time. Then, the method is used to manufacture stacked transformers for further application. Both inductors in stacked transformer are manufactured with the method, so signal transmission loss of the inductors is reduced. Because of the broadside coupling structure of stacked inductors, the coupling coefficient could be increased. Summing up the above reasons, the new type transformer has lower transmission loss. At the second part, the new type inductors are used to design 24GHz LNA and T/R switch. The usefulness of these new type inductors which shrinks chip size and improves performance of circuit with higher quality factor is confirmed with measurement data. At the third part, the new type transformers are used to design 24GHz LNA and T/R switch. The new type transformers are used to couple the loss signal to useful path. Therefore, signal loss in these circuits is reduced with the signal reuse method. Chip sizes are shrunk and circuit performances are improved by using these new type transformers.