2.4GHz調頻連續波雷達電路研製

Abstract

本論文使用整合設計及量測概念，研製2.4GHz調頻連續波雷達電路，在雷達電路中規劃數個子電路測試端點，不僅賦予更多彈性及重覆性，利於電路偵錯及了解，更使電路研製過程更具效率及把握性。 該雷達電路包含調變訊號控制電路、射頻訊號電路、發射及接收天線、基頻訊號處理電路，以及配合之電源電路。本論文研製之雷達電路組成，包含鋸齒波產生器、壓控振盪器、衰減器、電阻性功率分配器、功率放大器、低雜訊放大器、混波器、低通濾波器及運算放大器等元件。透過這些元件特性及系統規劃，經由整合設計、規劃、量測及製作一2.4GHz調頻連續波雷達，此研製經驗可套用至其他微波電路，達到更具有效率性。 論文第一章係簡介調頻連續波雷達，敘述其基本原理，以及整體電路架構規劃。第二章敘述所使用之元件特性、電路設計、佈局以及測試結果，如設計者了解元件特性、焊接考量及設計公式等，實不須進行元件電路製作及測試，直接可進行下章之整合測試過程。第三章則敘述整合電路之各階段電路，依序焊接、研製及量測，以及配合'2×2' 發射及接收圓極化天線之實際距離量測。第四章則為本論文設計及量測結果結論，並提出未來研究構想。

Through the concept of integration of design and test, a 2.4 GHz frequency-modulated continuous wave (FMCW) radar circuit is implemented. The main idea of this work is to set sub-circuits and test points under the full consideration of radar circuit. It not only gives more flexibility to understand and debug the sub-circuits but also implement the radar circuit more efficiently and reliably. The FMCW radar circuit consists of a signal modulation control circuit, a RF signal circuit, transmitting and receiving antennas, an IF signal processing circuit, and a power supply circuit. The implemented sub-circuits include a sawtooth generator, a voltage controlled oscillator, attenuators, a resistive power divider, power amplifiers, low noise amplifiers, a mixer, a low pass filter and operational amplifiers. A Matlab program of Fourier transformation is written to process the IF signals. Under the fully understanding of related devices and circuit planning, the implementation of a 2.4 GHz FMCW radar circuit is completed in one trial. We believe this experience can be applied to other microwave circuits. The first chapter briefly introduces the basic principle and configuration of the FMCW radar circuit. The second chapter depicts the characteristics of devices used in the radar circuit, and the design and measurement results of the sub-circuits. For designers who are already familiar with the characteristics of related devices, fabrication process, soldering considerations, and design formulas, they can progress to the next chapter. The third chapter describes the various stages of the integration and test of the radar circuit. A field test of the radar circuit and a '2×2' circularly polarized antenna array is conducted. The fourth chapter gives the conclusion and suggestion for the future work.