Please use this identifier to cite or link to this item:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/71659
Title: | 用於生成高功率微波之多鐵性材料非線性傳輸線 Multiferroic materials-based nonlinear transmission lines for high power microwaves generation |
Authors: | CHIA-LUN CHAO 趙家倫 |
Advisor: | 劉建豪(Chien-Hao Liu) |
Keyword: | 高功率微波,非線性傳輸線,孤立波,多鐵相性材料,電壓相依電感, High power microwaves,nonlinear transmission lines,solitary waves,multiferroic materials,voltage-dependent inductors, |
Publication Year : | 2018 |
Degree: | 碩士 |
Abstract: | 高功率微波是具備1MW以上之功率、工作頻率超過0.3 GHz之電磁波,常應用於國防與通訊系統。傳統上,須利用真空設備及強磁場將電子束的動能轉換為高功率微波,其缺點為體積大以及系統複雜。另一方法為,利用非線性傳輸線產生高頻電磁波,其原理為將高電壓與高電流的直流脈衝輸入具色散性介質之非線性傳輸線中,可輸出一高功率、高頻率之孤立波,其優點為體積小且系統較簡單。然而一般的非線性傳輸線的輸出頻率及功率往往受其內部元件的渦電流損失、遲滯效應以及介電弛豫影響,較難得到GHz以上的輸出,或具極大的能量損耗。
本研究提出應用多鐵相性材料組成的電壓控制電感之非線性傳輸線作為新的高功率微波源,藉由多鐵材料組成之電壓相依電感器,可降低使用高電流及介電質的需求,得到高頻、高功率之電磁波。本論文分為三部分,首先探討可調頻之非線性傳輸線,透過控制外部電壓以調整輸出訊號之頻率。接著探討可產生調頻脈衝(chirp)訊號之非線性傳輸線,可應用於雷達偵測系統。最後以多鐵相性非線性電感取代傳統非線性電容,透過純電壓控制電路,可產生GHz頻段之微波訊號,並達到MW的輸出功率。 High power microwaves (HPMs) are electromagnetic waves with the power level higher than 1 MW operated at the frequency above 0.3 GHz. They are often used in military applications and communication systems. Conventional HPM sources require vacuum equipment and strong magnetic fields for converting the kinetic energy of the electron beams into electromagnetic wave energy which are heavy and complicated. Another approach of generating HPMs is utilizing nonlinear transmission lines (NLTLs). Due to the characteristics of dispersions and non-linearity, the input high-voltage and high-current DC pulses are converted into solitary output waves with high power, and RF frequencies. Although they have compact sizes and simple systems, the output frequency and power levels of NLTLs can be affected by the eddy current loss, hysteresis, and dielectric relaxations. Hence, it is difficult to obtain GHz microwave output or they may consume lots of energy. In this research, we proposed a new type of NLTLs by exploiting a multiferroic-material based voltage-controlled inductors for generating HPMs. The main advantage was to reduce the need of high input currents and dielectric materials leading to high output microwave frequencies and high output power levels. The thesis included three parts. First, a tunable NLTL was proposed where the operating frequency of the output signal could be controlled by the external voltage. Next, a different NLTL was developed to generate chirp signals for radar applications. Last, a voltage-controlled NLTL composed of pure multiferroic nonlinear inductors was invented for generating HPMs with GHz frequency range and MW power level. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/71659 |
DOI: | 10.6342/NTU201900101 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 機械工程學系 |
Files in This Item:
File | Size | Format | |
---|---|---|---|
ntu-107-1.pdf Restricted Access | 13.19 MB | Adobe PDF |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.