新型推挽式射頻微機電開關之設計與應用

Abstract

本篇論文主旨乃是有鑑於傳統微波開關結構與重量過大,而小型半導體開關高頻特性不良,使傳統微波開關的使用受到侷限,故我們利用微機電(MEMS)技術製作射頻開關(RF switch),期能拓展微波開關的使用領域,我們所設計的射頻微機電開關以推挽式射頻微機電開關的觀念加以修改,與其他微機電開關相比,我們的微機電開關擁有與推挽式射頻微機電開關一樣的低驅動電壓,而且我們的微機電開關驅動控制電路簡單,類似翹翹板的結構,單一開關可切換高頻訊號於兩種路徑選擇,同時我們將此開關應用於一組二位元的移相器上,以獲得對高頻訊號移相的效果. 本篇論文是以推挽式射頻微機電開關的原理為立論，輔以Coventorware對微機電結構作機械應力模擬,而HFSS則對設計結構在1GHz到10GHz間進行模擬，並以微機電(MEMS)製程加以實現.

The research is in consideration of the disadvantages of conventional microwave switches, that is, the large volume and unbearable weight. Moreover, the semiconductor switches execute worse performance in the high frequency domain. As a result, we now exploit the MEMS technology to implement the RF switches to broaden its application. Our design is inspired by the conventional push-pull MEMS RF switch and some improvements are achieved, i.e., the simpler control circuits and higher occupational density. Our novel MEMS RF switch possesses as low voltage as others ever do; besides, it is in the shape of seesaw-like. Based on the mentioned design considerations, the novel switch can control two signal paths by one switch unit; furthermore, it can be combined with the phase shifter to direct the phases of signals. Our thesis is built on the concepts of push-pull switches with the simulation under the frequency from 1GH to 10GHz by HFSS. Beside, we also take the advantages of Coventorware to simulate the stress conditions. Finally, we implement our design through MEMS process.