射频可调滤波器技术的研究及应用

发布时间：2018-07-24 11:24

【摘要】：目前,随着移动用户对信息业务需求量的高速增长,频谱资源日益紧张,频谱资源的高效利用成为研究热点,认知无线电、三网融合、频谱感知等技术随之应运而生；有别于当前传统的通信系统,这些新技术使得通信系统能够动态地选择通信频段和信道,实现不同通信制式的融合和频谱资源的高效利用。但是,这样的动态频谱共享无线通信系统不能采用传统的固定频带的滤波器抑制干扰,而需要一种具有频率响应可重构特性的可调滤波器,动态地随着系统信道的改变调整滤波器的频率和带宽。本文针对动态频谱共享通信系统的关键技术与研究热点——可重构射频收发模块和可重构射频滤波器,开展深入的理论研究和实验验证, 论文的主要创新性工作和成果如下：1.首次提出一种结合耦合矩阵和非线性电流源的可调滤波器弱非线性分析方法,分析与预测加载变容二极管的可调滤波器的非线性产物,该方法适用于任意拓扑结构、任意分数带宽和采用绝大多数可调谐振器的可调滤波器设计；其次,分析了相对带宽、耦合拓扑结构和谐振器类型对可调滤波器非线性失真的影响,并给出相应减小非线性分量的可行途径。采用解析分析方法计算所得到的可调滤波器非线性分量与谐波平衡仿真结果一致,并且与电路实测结果相吻合,充分验证方法的有效性与准确性。上述研究结果已经发表于IEEE Trans. on MTT, vol.63, no.11,2015。2.提出一种目前最广义的耦合矩阵综合理论,突破目前传统耦合矩阵综合技术要求源和负载至少存在实数阻抗的限制。该方法基于功率波散射参数的定义,采用解析公式可将复数参考阻抗下的二端口散射参数直接转变为耦合网络的导纳矩阵,进而可以分别使用传统的留数方法和本征值优化方法获得横向耦合矩阵和特定拓扑结构的耦合矩阵,其源端和负载端参考阻抗均可以是任意复数阻抗,适用于任意拓扑结构。通过四阶全规范耦合矩阵和高阶复杂拓扑结构耦合矩阵的综合实例,充分验证该方法的有效性和可靠性。上述研究结果已经发表于IEEE MWCL, vol.25, no.6,2015.3.提出一种双路径电磁混合耦合的结构,用于绝对带宽恒定的可调滤波器设计。该结构主要是四分之一波长谐振器在短路端通过金属通孔进行磁耦合,在开路端通过平行耦合线进行电耦合,从而实现耦合系数曲线大小与斜率的独立控制。通过深入分析耦合机理并给出相应的综合设计方法,研制了恒定带宽为100MHz的可调滤波器加以验证。另一方面,为了同时提高可调滤波器的选择性和带外抑制度,提出了一种频率相关的输入输出馈电结构,研制了双极点恒定带宽可调滤波器,能够产生多至五个传输零点；上述研究结果已经分别发表于IEEE MWCL, vol.24, no.7,2014, IEEE MTT-SIMS2014。4.提出一种四分之一波长谐振器和双模谐振器混合结构,研制了四阶盒式结构的高选择性带通滤波器,相比传统的四阶盒式结构,结构紧凑、设计简单、加工容差大、选择性好。上述研究结果已经发表于IEEE MWCL, vol.24, no.12,2014,获得一项专利授权(专利号：ZL 2013 10552948.3)。5.在以上可调滤波器技术的研究基础上,研制了NGB-W的可重构直接变频射频收发前端。采用绝对带宽恒定的可调窄带滤波器动态选择信道,抑制干扰信号,实现对UHF频段频谱资源的动态高效利用。
[Abstract]:At present, with the rapid growth of the mobile users' demand for information services, the spectrum resources are becoming increasingly tense. The efficient utilization of spectrum resources has become a hot spot. Cognitive radio, triple network fusion and spectrum sensing have emerged as the times require, which are different from the current traditional communication systems. These new technologies make the communication system dynamically selected. The communication band and channel can achieve the fusion of different communication modes and the efficient utilization of spectrum resources. However, such a dynamic spectrum sharing wireless communication system can not use the traditional fixed band filter to suppress interference, but requires a tunable filter with frequency response reconfigurable characteristics, which dynamically changes with the change of the system channel. To adjust the frequency and bandwidth of the filter, this paper focuses on the key technologies and research hotspots of the dynamic spectrum sharing communication system - reconfigurable RF transceiver module and reconfigurable RF filter, and carries out in-depth theoretical research and experimental verification. The main innovative work and results of this paper are as follows: 1. a combination of coupling matrix is proposed for the first time. The nonlinear analysis method of tunable filter with nonlinear current source is used to analyze and predict the nonlinear product of the tunable filter for loading varactor. This method is suitable for arbitrary topology, arbitrary fractional bandwidth and adjustable filter set using most tunable vibrators. Secondly, the relative bandwidth and coupling topology are analyzed. The influence of the structure and resonator type on the nonlinear distortion of the tunable filter and the feasible way to reduce the nonlinear component are given. The analytical method is used to calculate the nonlinear component of the tunable filter, which is consistent with the harmonic balance simulation results, and is in agreement with the measured results of the circuit, and the validity and accuracy of the method are fully verified. The results of the above study have been published in IEEE Trans. on MTT, vol.63, and no.112015.2. to present a comprehensive theory of the most generalized coupling matrix, which breaks through the limitations of the current traditional coupling matrix synthesis technology requiring the source and load at least real impedance. Based on the definition of the parameters of the power wave scattering, the analytical formula can be used. The two port scattering parameters of the complex reference impedance are directly transformed into the admittance matrix of the coupled network, and then the coupling matrix of the transverse coupling matrix and the specific topology can be obtained by using the traditional residue method and the eigenvalue optimization method respectively. The reference impedance of the source end and the load end can be arbitrary complex impedance, and it is applicable to arbitrarily. The effectiveness and reliability of the method are fully verified by a comprehensive example of four order fully normalized coupling matrices and high order complex topology coupling matrices. The results of the above study have been published in IEEE MWCL, Vol.25, and no.62015.3. for a dual path electromagnetic hybrid structure for constant bandwidth constant tunable filtering. The structure of the 1/4 wavelength resonator is mainly magnetic coupling through a metal through hole in the short circuit, and the electric coupling is carried out through the parallel coupling line at the open end, thus realizing the independent control of the size and slope of the coupling coefficient curve. The constant bandwidth is developed by analyzing the coupling mechanism and giving the corresponding comprehensive design method. To verify the 100MHz tunable filter, on the other hand, in order to improve the selectivity of the tunable filter and the band suppression system at the same time, a frequency dependent input and output feed structure is proposed. A constant bandwidth tunable filter for a bipolar point is developed, which can produce more than five transmission zeros. The above results have been published in IEE, respectively. E MWCL, Vol.24, no.72014, IEEE MTT-SIMS2014.4. proposed a hybrid structure of 1/4 wavelength resonator and dual mode resonator, and developed a high selective band pass filter for the four order box structure. Compared with the traditional four order box structure, the structure is compact, the design is simple, the addition tolerance is large, and the selectivity is good. The above results have already published in IE EE MWCL, Vol.24, no.122014, obtained a patent license (patent number: ZL 201310552948.3).5. on the basis of the research of the above tunable filter technology, developed a reconfigurable direct frequency frequency transceiver front end of NGB-W. The channel of dynamic selection of the tunable narrow band filter with absolute bandwidth constant is used to suppress the interference signal and realize the UHF frequency band. The dynamic and efficient utilization of spectrum resources.
【学位授予单位】：东南大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN713

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