含平衡式表面聲波振盪器短距離發射晶片之研究

Abstract

本論文在於使用金氧半製程研究具有差動輸出之平衡式表面聲波振盪器，此雙晶片振盪模組工作於434 MHz，具有振幅鍵控、頻率鍵控的功能，其調變速率最大為400kbit/sec，頻偏為26 kHz。經由電源開關的控制可以達到休眠時間的低功率消耗，提升電池使用時間。除了表面聲波共振腔為外掛，電路部份使用TSMC 1P5M 0.25μm CMOS製程實現，以縮小電路體積；此兩晶片安置於TO-39封裝內形成一發射器模組以降低成本。信號的輻射則依靠外部印刷電路板上的小型迴路天線。經由適當的設計，使用印刷電路板上的金屬導線形成等效電感與電容，來做為天線與發射器電路間的阻抗匹配以達到最大功率傳輸，可取代實體之被動元件，達到無須使用外部元件的目標。

The purpose of this study is to develop a balance SAW oscillator with differential outputs using CMOS process. The oscillator with a SAW resonator is designed. The circuit fabricated by TSMC 0.25um CMOS process has the functions of ASK, and FSK modulations under 2.5V power supply. The maximum switching speed reaches 400kbps and offset frequency is 26 kHz. Using TO-39 metal can package, the CMOS and SAW resonator chips can be put together to form a multi chip transmitter module for cost reduction. For signal radiation, a small loop antenna is employed. To achieve conjugate matching, a transformer and small capacitors are required by utilizing the metal trace on the PC Board.