小型化双频微波无源器件关键技术的研究
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摘要
随着射频通信系统突飞猛进的发展,无线设备越来越向小型化,便携性的方向进步。同时通讯标准的多元化,促进了双频或多频射频系统的诞生。如何将组成单频系统的微波器件扩展到双频以及如何实现双频微波器件的小型化成为了具有重要意义的研究课题。为了实现这一目标,本论文针对几种微波无源器件的小型化和双频设计展开了一系列的研究。
本论文创新性研究成果包括：
1.研究了频率依赖性复数阻抗变换理论,提出了三种由一段传输线和一个并联枝节构成的新型双频阻抗变换器结构。它们可以在两个频段内同时满足将频率依赖性复数负载阻抗匹配至50欧标准源阻抗或频率依赖性复数源阻抗。论文推导出实现该结构的数学表达式,并对其进行了仿真和实验验证。这部分成果以学术论文形式发表在国际著名微波会议：Asia Pacific Microwave Conference2012上。
2.提出了一种改进的小型化双频不等分威尔金森功分器。通过利用慢波结构替代原有的微带线,将双频不等分威尔金森功分器的尺寸减小为原来的71.6%。通过仿真和实物测试对比,进一步验证了该设计的有效性。这部分成果以学术论文形式发表在国际著名微波会议：Asia Pacific Microwave Conference2012上。
3.提出了一种不附加任何枝节线的小型化环形混合网络结构。通过ABCD矩阵和偶奇模分析,得到轴对称结构下等分环形混合网络的小型化设计,解决了环形混合网络占用电路面积过大的难题。在此基础上,进一步提出了不等分环形混合网络的小型化结构。该结构具有两个自由变量,可实现极大的功分比而不受传输线特征阻抗的限制。通过仿真和实物测试验证了该方法的有效性。这部分成果以多篇论文的形式发表在期刊：Journal of Electromagnetic Waves and Applications和Journal of Convergence Information Technology上。
4.提出了具有一个附加枝节的双频环形混合网络结构。通过在传统环形混合网络结构上添加一段开路或短路枝节,可实现同时工作于两个频率的环形混合网络。论文推导出实现该结构的闭式解析公式,通过电路仿真证明了结构的可行性。在此基础上进一步提出了一种双频不等分环形混合网络。讨论了该结构的几种特例。通过仿真和实物测试对该方法进行了验证。
With the rapid development of wireless communications, the wireless devices are gradually improved towards miniaturization and portablity. At the same time, the diversity of communication protocol promotes RF system to dual-band and even multi-band system. How to extend the single band microwave components, which make up traditional single band system, to dual-band ones and how to realize the miniaturization of the dual-band microwave components are of great significance. For this goal, this thesis investigates the miniaturization and dual-band design of microwave passive components.
The contributions of this thesis are as follows:
1. By analyzing the principle of frequency-dependent complex impedance transformer, I propose three novel miniaturization dual-band transformers. They are composed of one transmission line and a shunt stub. They can transform a frequency-dependent complex load to a standard50Ω or to a frequency-dependent complex source at two frequencies simultaneously. This thesis derives the design formulas of these structures and verifies them by simulation and measurement. This part, as the academic paper, has been published in Asia Pacific Microwave Conference2012. And one patent is applied.
2. A compact dual-band unequal Wilkinson power divider is proposed. By theory analyzing and formulas deducing, the miniaturization of dual-band unequal Wilkinson power divider is realized using slow wave structure. A prototype is fabricated and the size is reduced by71.6%. By comparing the simulation and measurement, the exactness of this method is further proved. This part, as the academic paper, has been published in Asia Pacific Microwave Conference2012.
3. A compact180°rat race hybrid without any additional stub is proposed. By ABCD matrixes and even-odd mode analyzing, the minimum of rat race hybrid for axial symmetry is obtained, which solves the area problem of rat race hybrid. On its basis, the miniaturization of unequal rat race hybrid is investigated deeply. The design equations are concluded based on the theory of transmission line. By adjusting two variables, this structure can realize maximum power division without the limit of the impedance value of transmission line. The design is confirmed by simulation and measurement. This part, as the academic papers, has been published in Journal of Electromagnetic Waves and Applications and Journal of Convergence Information Technology.
4. The dual-band rat race hybrids with single additional stub are established. By adding an open or shorted stub to the traditional rat race hybrid, the rat race hybrid can work at two different frequencies. The closed-form design equations of this structure are derived mathematically and the validity is proved by circuit simulation. Furthermore, a dual-band unequal rat race hybrid with similar structure is proposed. Moreover, special cases are discussed. Simulations and measurements are performed to validate the approach.
本论文创新性研究成果包括：
1.研究了频率依赖性复数阻抗变换理论,提出了三种由一段传输线和一个并联枝节构成的新型双频阻抗变换器结构。它们可以在两个频段内同时满足将频率依赖性复数负载阻抗匹配至50欧标准源阻抗或频率依赖性复数源阻抗。论文推导出实现该结构的数学表达式,并对其进行了仿真和实验验证。这部分成果以学术论文形式发表在国际著名微波会议：Asia Pacific Microwave Conference2012上。
2.提出了一种改进的小型化双频不等分威尔金森功分器。通过利用慢波结构替代原有的微带线,将双频不等分威尔金森功分器的尺寸减小为原来的71.6%。通过仿真和实物测试对比,进一步验证了该设计的有效性。这部分成果以学术论文形式发表在国际著名微波会议：Asia Pacific Microwave Conference2012上。
3.提出了一种不附加任何枝节线的小型化环形混合网络结构。通过ABCD矩阵和偶奇模分析,得到轴对称结构下等分环形混合网络的小型化设计,解决了环形混合网络占用电路面积过大的难题。在此基础上,进一步提出了不等分环形混合网络的小型化结构。该结构具有两个自由变量,可实现极大的功分比而不受传输线特征阻抗的限制。通过仿真和实物测试验证了该方法的有效性。这部分成果以多篇论文的形式发表在期刊：Journal of Electromagnetic Waves and Applications和Journal of Convergence Information Technology上。
4.提出了具有一个附加枝节的双频环形混合网络结构。通过在传统环形混合网络结构上添加一段开路或短路枝节,可实现同时工作于两个频率的环形混合网络。论文推导出实现该结构的闭式解析公式,通过电路仿真证明了结构的可行性。在此基础上进一步提出了一种双频不等分环形混合网络。讨论了该结构的几种特例。通过仿真和实物测试对该方法进行了验证。
With the rapid development of wireless communications, the wireless devices are gradually improved towards miniaturization and portablity. At the same time, the diversity of communication protocol promotes RF system to dual-band and even multi-band system. How to extend the single band microwave components, which make up traditional single band system, to dual-band ones and how to realize the miniaturization of the dual-band microwave components are of great significance. For this goal, this thesis investigates the miniaturization and dual-band design of microwave passive components.
The contributions of this thesis are as follows:
1. By analyzing the principle of frequency-dependent complex impedance transformer, I propose three novel miniaturization dual-band transformers. They are composed of one transmission line and a shunt stub. They can transform a frequency-dependent complex load to a standard50Ω or to a frequency-dependent complex source at two frequencies simultaneously. This thesis derives the design formulas of these structures and verifies them by simulation and measurement. This part, as the academic paper, has been published in Asia Pacific Microwave Conference2012. And one patent is applied.
2. A compact dual-band unequal Wilkinson power divider is proposed. By theory analyzing and formulas deducing, the miniaturization of dual-band unequal Wilkinson power divider is realized using slow wave structure. A prototype is fabricated and the size is reduced by71.6%. By comparing the simulation and measurement, the exactness of this method is further proved. This part, as the academic paper, has been published in Asia Pacific Microwave Conference2012.
3. A compact180°rat race hybrid without any additional stub is proposed. By ABCD matrixes and even-odd mode analyzing, the minimum of rat race hybrid for axial symmetry is obtained, which solves the area problem of rat race hybrid. On its basis, the miniaturization of unequal rat race hybrid is investigated deeply. The design equations are concluded based on the theory of transmission line. By adjusting two variables, this structure can realize maximum power division without the limit of the impedance value of transmission line. The design is confirmed by simulation and measurement. This part, as the academic papers, has been published in Journal of Electromagnetic Waves and Applications and Journal of Convergence Information Technology.
4. The dual-band rat race hybrids with single additional stub are established. By adding an open or shorted stub to the traditional rat race hybrid, the rat race hybrid can work at two different frequencies. The closed-form design equations of this structure are derived mathematically and the validity is proved by circuit simulation. Furthermore, a dual-band unequal rat race hybrid with similar structure is proposed. Moreover, special cases are discussed. Simulations and measurements are performed to validate the approach.
引文
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