K-頻段微波輻射計之量測

Abstract

本論文敘述使用安捷倫PNA系列微波網路分析儀，量測一K-頻段微波輻射計之特性。首先，第一章介紹微波輻射計之背景及應用，由於微波輻射計係用以接收觀測物體之雜訊，因此微波輻射計及其各模組之校準亦為量測重點。接著於第二章討論散測參數之定義與量測原理，由於微波輻射計包含頻率轉換元件，因此關於頻率移置之散射參數與其校準，也在本章予以討論。隨後於第三章說明微波網路分析儀的工作原理、校準方式與其使用考量。安捷倫PNA系列微波網路分析儀，於雜訊指數的量測有別於常見的Y-指數法，其使用之冷式源端法量測原理亦在本章說明。第四章則分別敘述K-頻段微波輻射計中，各模組及整合之量測架構，以及量測結果。

This thesis presents measurements of a K-band microwave radiometer using Agilent performance network analyzers (PNAs). The background of microwave radiometer is firstly introduced in Chapter 1. Since radiometer is an instrument to process received noises, its measurement arrangement and calibration are of great importance. The definition and calibration of scattering parameter (S-parameter) and frequency-offset S-parameter are explained in Chapter 2, since the radiometer consists of frequency-converting devices. Then, the operation priciple and calibration of PNA are explained in Chapter 3. The noise measurement technique of PNA, different from the traditional Y-factor method, the cold-source method is also explained. Finally, measurement arrangements and results of a K-band radiometer including modules are presented in Chapter 4.