射频微带线性相位滤波器的设计

发布时间：2019-05-19 07:44

【摘要】：在移动通信飞速发展、微波电路高度集成化的今天，微波电路的发展越来越得到重视，微波滤波器在通信系统滤波元件中占据重要位置，，其中，在单片微波电路里，微带线被称为其主要载体以传输信号，而带通滤波器在微波电路里发展最为迅速，对于接收机等很多系统，带通滤波器对其性能的好坏起到决定性的作用，所以对微带线带通滤波器进行理论角度的分析、结构方面的研究等都已经成为非常受重视的课题。如今，考虑到无源网络传输信号的可靠性，滤波器相频特性已经变得和幅频特性同样重要，因此，在微波电路的设计中，研究设计线性相位带通滤波器并加以优化将成为十分有价值的研究项目。本文首先由归一化低通滤波器出发，通过分析滤波器的特性，推算出其线性相位设计参数，然后对基于分布参数实现带通滤波电路的设计原理进行理论分析，在此基础上完成平行耦合微带线结构的设计流程和相关参数计算，最后设计一个中心频率为2GHz的平行耦合微带线线性相位带通滤波器。本课题是对滤波器的相频特性和幅频特性同时进行优化，并且在得到最优通带平坦度的同时，使阻带具有尽量大的衰减。通过设计实例的仿真结果以及经过优化的仿真结果，验证此方法正确可行、简单高效。在微带线优化方面，本文提出了一种新的算法，以理想的微带线尺寸参数为基础，建立理想传递函数作为目标函数，同时在理想参数周围定义取值范围，将取值范围内的参数限定在一定数量级精度内，在此范围内搜索符合条件的参数，并建立各自的传递函数，最后将所有传递函数与目标函数比较，最接近目标函数的一个为最优函数，构成最优函数的微带线尺寸参数便是最优参数。在优化结果验证方面，本文利用与实际电路测试最为相似的矩量仿真方法，对优化后的电路进行板图仿真，虽然由于时间关系，电路板还在制作当中，但矩量法的仿真结果与实际电路十分接近，可以证明目标函数法有效可行。
[Abstract]:With the rapid development of mobile communication and the high integration of microwave circuits, more and more attention has been paid to the development of microwave circuits. Microwave filters occupy an important position in the filter elements of communication systems, among which, in a single microwave circuit, Microstrip line is called its main carrier to transmit signal, and bandpass filter develops most rapidly in microwave circuit. For many systems such as receiver, bandpass filter plays a decisive role in its performance. Therefore, the theoretical analysis and structural research of microstrip band-pass filter have become a very important topic. Nowadays, considering the reliability of passive network transmission signal, the phase frequency characteristic of filter has become as important as amplitude frequency characteristic. Therefore, in the design of microwave circuit, The research and optimization of linear phase bandpass filter will become a very valuable research project. In this paper, based on the normalized low-pass filter, the linear phase design parameters are calculated by analyzing the characteristics of the filter, and then the design principle of band-pass filter circuit based on distributed parameters is analyzed theoretically. On this basis, the design flow and related parameters calculation of parallel coupling microstrip line structure are completed. Finally, a parallel coupled microstrip line linear phase bandpass filter with central frequency 2GHz is designed. In this paper, the phase frequency characteristics and amplitude frequency characteristics of the filter are optimized at the same time, and the optimal passband flatness is obtained, and the stopband is attenuated as much as possible. Through the simulation results of the design example and the optimized simulation results, it is verified that the method is correct, feasible, simple and efficient. In the aspect of microstrip line optimization, a new algorithm is proposed in this paper. Based on the ideal microstrip line size parameters, the ideal transfer function is established as the objective function, and the value range is defined around the ideal parameters. The parameters in the range of values are limited to a certain order of magnitude precision, and the parameters that meet the conditions are searched in this range, and their respective transfer functions are established. Finally, all the transfer functions are compared with the objective functions. One of the closest to the objective function is the optimal function, and the microstrip line size parameter that constitutes the optimal function is the optimal parameter. In the aspect of verification of optimization results, this paper uses the moment simulation method, which is most similar to the actual circuit test, to simulate the optimized circuit board, although the circuit board is still in the process of making because of the time relationship. However, the simulation results of the moment method are very close to those of the actual circuit, which can prove that the objective function method is effective and feasible.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713

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