38GHz雷達前端電路設計

Abstract

本論文將介紹38GHz雷達前端電路設計，為一車裝系統的前端架構。其主要目的為測速與測距－幫助駕駛者在雨天或有霧的天氣，因為視覺的不良，而發生危險。本論文包含了整合接收機與發射機的單級設計方法、製造和量測。其中發射端與接收端均使用Duroid-5880 板材製作，操作頻段38GHz。 第二章介紹前視雷達的基本理論與操作原理。第三章包含了各單級元件的設計理論，模擬，與實作。其中雷達需要一個線性度良好，穩定，相位雜訊低的source，我們應用了微波鑑鎖頻器所構成的鎖頻迴路來達成此一目的。此transceiver使用模組化的架構，利用三倍頻器將頻段昇頻至毫米波段，如此易除錯且降低成本。其中單級包括有VCO，Mixer，Tripler，BPF，Amplifier，MMIC，Coupler，等等..，均使用微帶線來作設計。所設計的38GHz Rate-Race Mixer之C/L=-7~-8dB(@38.1~38.4GHz)，對接收機而言，雜訊指數亦貢獻7~8dB；Anti-parallel Diode Tripler 之C/L=-17dB，其值雖大，但對於Millimeter Wave而言，可降低空腔的效應，亦可避免振盪的發生。 第四章為Transceiver的量測結果與未來的研究方向，可朝向均以MMIC作設計，如此可使尺寸縮小，降低成本。且如何運用DSP(數位訊號處理器)來顯示與計算速度與距離，將是下一階段的研究重點。

This thesis illustrates the necessity and design process of the front-end circuit design of 38GHz radar for use in vehicular applications. A qualitative discussion of the need for and applications of a simple low cost transceiver system is presented first. A closer look at a system componentsrequirement are presented well. The second portion of the thesis focuses on the understanding electromagnetic theories that radar is built upon. The radar range equation, frequency linearity, etc…are all discussed with relation to the design process. Parameters in the choice of frequency modulated continuous wave radar are given to support the choice in radar type. The experimental design procedure for the radar system is presented in detail. Every component of the radar system is examined with respected to its electrical and functional aspects. Every components experimental test results are given to illustrate the success of the design procedure and to support choices of specific hardware types.