高选择性平面微带滤波器的分析与设计

发布时间：2018-06-22 12:52

本文选题：平面微带滤波器 + 传输零点　；参考：《南京理工大学》2017年硕士论文

【摘要】：微波滤波器是现代无线通信和雷达等系统的射频前端的重要器件。随着现代技术的快速发展,电子产品集成度越来越高,也就意味着对滤波器平面化和小型化的要求更高。同时,频谱资源日趋紧张的现状对滤波器的通带频率选择性和带外抑制度也提出了更高的要求。多频滤波器能够同时兼容多种通信资源,平衡滤波器能够有效地抑制共模干扰,因此被广泛地应用于通信或雷达领域。本论文主要从增加滤波器传输零点的角度出发,结合不同的谐振器,设计实现了多种高选择性和高带外谐波抑制度的微波滤波器。主要研究工作包括:1.高选择性带通滤波器及双工器的设计:结合开路/短路形式的双重行为谐振器(DBR),设计了两种高频率选择性的带通滤波器,在上阻带分别实现了 3个和6个传输零点,设计结构紧凑;另外,在不影响带内传输特性的情况下,可以通过调节开路/短路支节线电长度,改变传输零点在通带两侧的位置,提高了上阻带抑制度。进一步地,在DBR滤波器的基础上,利用T型结设计了一个高隔离度的双工器。2.高选择性双频带通/带阻滤波器的设计:提出了不等长λ/4阶跃阻抗谐振器(SIR)的谐振特性理论,利用两个对称的λ/4 SIR设计实现了两种双频带通滤波器,通过两个谐振器之间的耦合产生可控传输零点。提出了基于开路/短路耦合线的双频带阻滤波器,通过奇偶模分析方法详细分析了多个带外传输极点的产生原因,并在此基础上加载变容管,设计了上阻带固定不变、下阻带中心频率可调节的双频带阻滤波器。3.高选择性宽带平衡滤波器的设计:结合开路/短路耦合线特性,提出了两个分别具有4个和6个传输零点的高选择性平衡滤波器,在三倍频内都实现了较高的共模抑制;差模响应的通带特性和共模响应的抑制特性主要由加载支节的开路耦合线产生,传输零点主要由两路信号能量相消和加载的支节产生。
[Abstract]:Microwave filter is an important part of RF front end in modern wireless communication and radar systems. With the rapid development of modern technology, the integration of electronic products is becoming more and more high, which means that the flatness and miniaturization of filters are higher. At the same time, the increasing shortage of spectrum resources puts forward higher requirements for passband frequency selectivity and out-of-band suppression of filters. Multi-frequency filters can be compatible with multiple communication resources at the same time, and balanced filters can effectively suppress common-mode interference, so they are widely used in the field of communication or radar. In this paper, we design and implement a variety of microwave filters with high selectivity and high suppression of out-of-band harmonics from the point of view of increasing the transmission zeros of filters and combining with different resonators. The main research work includes: 1. Design of highly selective bandpass filter and Duplexer: two kinds of high frequency selective bandpass filters are designed in combination with open circuit / short circuit dual behavior resonators (DBR). Three transmission zeros and six transmission zeros are realized in the upstopband, respectively. The design structure is compact and the position of transmission zero on both sides of the passband can be changed by adjusting the electric length of the open / short circuit branch without affecting the in-band transmission characteristics and the suppression degree of the upper stopband can be improved. Furthermore, on the basis of DBR filter, a high isolation Duplexer. 2 is designed by using T junction. Design of highly selective Dual-band Bandpass / Bandstop filters: the resonant characteristic theory of 位 / 4-step impedance resonator (Sir) with unequal length is proposed. Two kinds of dual-band band-pass filters are realized by using two symmetrical 位 / 4SIR designs. A controllable transmission zero is generated by coupling between two resonators. A dual-band stopper filter based on open-circuit / short-circuit coupling line is proposed. The causes of multiple out-of-band transmission poles are analyzed in detail by using the odd-even mode analysis method. On this basis, the capacitive tube is loaded and the upper stopband fixed invariant is designed. Lower stopband center frequency adjustable double band stopper filter. 3. Design of high selective wideband balanced filter: two high selective balanced filters with 4 and 6 transmission zeros are proposed in combination with open circuit / short circuit coupling line characteristics, which can achieve high common mode suppression in tripling frequency. The passband characteristic of the differential mode response and the suppression characteristic of the common mode response are mainly generated by the open-circuit coupling line of the loaded branch, and the transmission zeros are mainly generated by the two-channel signal energy cancellation and the loaded branch node.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN713

【相似文献】