近年來,頻率可重構天線因其能夠響應系統要求和環(huán)境條件調整工作頻帶而在現代無線應用中引起了越來越多的關注。許多新應用需要研究和設計頻率可重構天線,如認知無線電（CR）,先進移動技術,設備到設備通信,多輸入多輸出（MIMO）系統等。頻率可重構天線可以與MIMO系統結合使用,以獲得頻率可重構天線提供的優(yōu)勢,同時保持MIMO功能。頻率可重構MIMO天線可以增強信道容量并提供更高的數據速率傳輸。因此,具有MIMO配置的頻率可重構天線對于現代無線通信系統是非常期望的。本文目的是設計和實現具有緊湊尺寸的MIMO配置的新型頻率可重構天線,適用于無線手持設備。本研究中提出的天線提供了寬范圍的連續(xù)頻率調諧,同時保持了良好的MIMO性能。此外,還提出了一種能夠進行傳感和通信的單個天線用于CR應用。在這些設計中采用薄型結構（貼片,槽和單極）。所提出的設計的優(yōu)點是其緊湊的原型,成本有效,低輪廓,平面結構和寬頻率可重配置性,每個天線元件僅使用一個變容二極管。本文首先提出了一種基于微帶饋線的雙頻段可重構MIMO貼片天線設計。天線包括四個對稱放置的矩形貼片天線元件。將雙重用途的六邊形缺陷接地結構（DGS）引入接地平面... 

【文章來源】：華北電力大學(北京)北京市 211工程院校 教育部直屬院校

【文章頁數】：124 頁

【學位級別】：博士

【文章目錄】：
Abstract
摘要
Acronyms and Abbreviations
List of Symbols
Chapter 1 Introduction
    1.1 Motivation
    1.2 Objectives
    1.3 Research Contributions
    1.4 Thesis Organization
Chapter 2 The Background of Frequency Reconfigurable MIMO Antennas
    2.1 Reconfigurable Antennas
        2.1.1 Classification of Reconfigurable Antennas
        2.1.2 Reconfiguration Methods Employed to Implement Reconfigurable Antennas
            2.1.2.1 Frequency Reconfiguration using RF-MEMS
            2.1.2.2 Frequency Reconfiguration using PIN Diodes
            2.1.2.3 Frequency Reconfiguration using Varactor Diodes
        2.1.3 Applications of Frequency Reconfigurable Antennas
            2.1.3.1 Cognitive Radio
    2.2 Review of Previously Designed Frequency Reconfigurable Antennas
        2.2.1 Frequency Reconfigurable Patch Antennas
        2.2.2 Frequency Reconfigurable Slot Antennas
        2.2.3 Frequency Reconfigurable Monopole Antennas
    2.3 Frequency Reconfigurable MIMO Antennas
        2.3.1 Review of Previously Designed Frequency Reconfigurable MIMO Antennas
    2.4 Research Gaps to be Filled
Chapter 3 Frequency Reconfigurable Patch Antennas with Reconfigurable MicrostripFeedline
    3.1 A Compact Frequency Reconfigurable Patch Antenna with Agile MicrostripFeedline
        3.1.1 Introduction
        3.1.2 Antenna Geometry
        3.1.3 Results
            3.1.3.1 S-Parameters
            3.1.3.2 Gain Patterns and Efficiency
            3.1.3.3 State-of-the-Art-Comparison
    3.2 Two-Element Frequency Agile MIMO Patch Antenna with Agile FeedingMechanism
        3.2.1 Introduction
        3.2.2 Antenna Structure
        3.2.3 Results
            3.2.3.1 Isolation Results
            3.2.3.2 Radiation Patterns
            3.2.3.3 Envelope Correlation Coefficient
    3.3 Four-Element Dual Band Frequency Reconfigurable MIMO Patch-Slot AntennaBased on Reconfigurable Microstrip Feedline
        3.3.1 Introduction
        3.3.2 Antenna Layout
            3.3.2.1 Antenna Configuration
            3.3.2.2 Single Element Antenna
        3.3.3 Results and Discussion
            3.3.3.1 S-Parameters
            3.3.3.2 Radiation Patterns and Efficiency
            3.3.3.3 Envelope Correlation Coefficient
    3.4 Conclusion
Chapter 4 An Eight-Element Frequency Reconfigurable MIMO Slot Antenna with Multi-Band Tuning Characteristics
    4.1 Introduction
    4.2 Antenna Layout
        4.2.1 Biasing Circuit
    4.3 Simulated vs Measurement Results
        4.3.1 S-Parameters
        4.3.2 Radiation Patterns and Efficiency
        4.3.3 ECC and TARC
        4.3.4 Current Distribution
        4.3.5 State-of-the-Art-Comparison
    4.4 Conclusion
Chapter 5 A Reconfigurable MIMO/UWB MIMO Antenna Design for Cognitive RadioApplications
    5.1 Introduction
    5.2 Antenna Layout
        5.2.1 UWB MIMO Sensing Antenna
        5.2.2 Reconfigurable MIMO Antenna
    5.3 Results
        5.3.1 UWB MIMO Spectrum Sensing Mode
        5.3.2 Frequency Reconfigurable MIMO Mode
        5.3.3 Radiation Patterns and Efficiency
        5.3.4 Envelope Correlation Coefficient
        5.3.5 Current Distribution
        5.3.6 State-of-the-Art-Comparison
    5.4 Conclusion
Chapter 6 Conclusion and Future Work
    6.1 Conclusion
    6.2 Future Work
References
Published Papers
Acknowledgements
About the Author



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