DGS技术在微带无源电路中的应用

【作者】 周虹；

【导师】 顾继慧；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2009， 硕士

【摘要】 缺陷接地结构(DGS)由光子带隙(PBG)结构发展而来,是在微波电路的接地面上蚀刻出周期或非周期性的缺陷图案,DGS具有单极点低通特性、慢波特性和高等效特性阻抗等特性,若将其合理地应用于微波平面电路中可改善微波集成电路的性能,如抑制谐波、增加阻带带宽和减小尺寸等,近年来DGS逐渐成为微波电路设计领域的一个研究热点。本文的主要工作首先是对DGS的传输特性进行分析。根据DGS的单极点低通特性和LC等效电路理论,推导了DGS的LC等效电路,并通过电磁仿真和电路仿真对其进行验证。借助于三维电磁仿真软件和LC等效电路,分析了哑铃形DGS各参数对其电路特性的影响,并进行详细的总结。通过电磁仿真对DGS的缺点也进行了阐明,即DGS的引入会在接地板下方产生较大的电磁波辐射,对周围电路产生影响,在此基础上提出了一种改良的采用蛇形缝隙的新型DGS。其次详细介绍了DGS应用于微带无源电路中的设计。利用DGS的单极点低通特性分别设计了一个由四个不同DGS单元级联构成的微带低通滤波器和应用单个不对称DGS设计的新型微带双工器;利用DGS的高等效特性阻抗特性设计并实现了1:4不等功分比功分器,并根据所设计的滤波器和功分器的模型和尺寸加工出了实物,仿真和测试结果的良好吻合证明了DGS在微带电路应用中的有效性和实用性。更多还原

【Abstract】 Defected Ground Structure (DGS) is a periodic or nonperiodic defected pattern etched on the ground plane of microwave circuit, which is extended from Photonic Band-Gap (PBG) Structure. DGS has many characteristics that are single pole and low pass, slow wave and high effective characteristic impedance and so on. If it is applied in microwave plane circuits reasonably, it may greatly improve the performance of microwave integrated circuits (MIC), such as suppressing harmonic response, enlarging stopband bandwidth and reducing size and so on, so DGS is becoming a research hotspot of MIC design domain in recent years.Firstly, the main work of this thesis is analyzing the transmission characteristic of DGS. According to the DGS characteristic of single pole and low pass and the theory of the LC equivalent circuit, the LC equivalent circuit of DGS is researched and validated by electromagnetic simulations and circuit simulations. With the help of 3-D electromagnetic simulation software and the LC equivalent circuit, the effect of changing several parameters of dumbbell shaped DGS is discussed and summarized particularly. .The drawback of DGS is analyzed by simulation too, etching DGS may lead electromagnetic radiation to the ground plane and have an impact on the surrounding circuit, so a new improved type of DGS with the snake-like gap is proposed.Then DGS is applied in the design of microstrip passive circuits in detail. Based on the DGS characteristic of single pole and low pass, a microstrip low-pass filter which is composed of four different cascaded DGS units and a new microstrip diplexer which is consist of asymmetric DGS are designed; Using the DGS characteristic of high effective characteristic impedance, a 1:4 unequal power divider is proposed and realized. And the designed filter and power divider are processed in accordance with their models and sizes, the good agreement between simulation and test results shows the validity and feasibility of the application of DGS in the circuits.更多还原