摘要混合环是微波,毫米波系统中的重要器件，在电路及天线馈电系统中有着许多应用。小型化的90°宽带混合环已有许多不同的应用，但是，小型化的180°宽带混合环开发仍较少。为此，人们利用了许多方式来减小180°混合环的尺寸。比如缩小圆环周长，采用折叠线等等。随着带宽需求的持续增长，如何提高混合环的频带宽度也成为人们感兴趣的课题之一。双面平行带线（DSPSL）是一种新型微波传输线，相对于微带线和共面波导，有着许多优势，比如易于实现平衡/差分电路结构，易于实现低特性阻抗，易于设计反相器等等。本论文提出了一种使用短截线和反相器来设计双面平行带线宽带混合环的新方案。采用反相器后，小型化混合环的体积减小为传统混合环的67%。混合环3dB相对带宽为58%（2.1-3.8GHz）, 最大幅度不平衡性小于0.65dB。在工作频段内，相位不平衡性小于6°，隔离度大于25dB,反射损耗高于20dB。本设计的理论计算和软件仿真结果吻合得较好，验证了设计思路的可行性。9712
关键词 混合环 宽带 反相器 短截线 双面平行带线
毕业设计说明书（论文）外文摘要
Title A Broadband Rat-race Hybrid Using the DSPSL
Abstract
The hybrid coupler is one of the most fundamental building blocks in microwave and millimeter-wave systems，with many applications in circuits and antenna feed systems. Publications on miniaturized wide-band 90° hybrids for various applications are numerous, but compact wide-band 180° hybrids are less proposed. Many methods have been developed to reduce the size of the rat-race hybrid. Reducing ring perimeter, folded lines, artificial transmission lines, periodic stepped-impedance resonator structure, coupled lines and lumped elements are miniaturization strategies， employed to reduce the size of the microstrip rat-race hybrid. The bandwidth enhancement of the rat-race hybrid is now becoming a hot topic, since the bandwidth demands of broadband applications keep increasing. Double-sided parallel strip line (DSPSL) is a versatile microwave transmission line. Compared with the microstrip line and coplanar waveguide (CPW), DSPSL takes many advantages, such as easy realization of the balanced microwave circuits, simple implementations for the low characteristic impedance line, and also the phase inverter etc. In this thesis, a new wideband DSPSL hybrid using phase inverter with stubs is proposed. Using the phase inverter, the size of the miniaturized rat-race hybrid is 67% of the conventional one. The 3dB bandwidth with a maximum amplitude unbalance of less than 0.65dB is 58% from 2.1 to 3.8 GHz. Over this frequency band, the phase variation is ±6°, the isolation is greater than 25dB and the return loss is greater than 15dB. The overall computed and simulated results show good agreement with this proposed design, indicating the validity of the proposed strategies.
Key Words hybrid coupler, wideband, phase inverter, stubs, double-sided parallel strip line( DSPSL)
目 录
1 绪论 2
1.1 本课题的研究背景 2
1.2 国内外研究状况 3
1.3 本课题的主要工作 4
2 基本混合环介绍 6
2.1 混合环原理及特性 6
2.2 混合环分析方法 7
2.3 本章小结 9
3 DSPSL分析及应用 10
3.1 DSPSL基本结构 10
3.2 DSPSL特性分析 11
3.2.1 DSPSL场的分布 11
3.2.2 DSPSL特性阻抗的计算 11
3.2.3 带有插入导体平面的DSPSL 12 基于双面平行带线的宽带混合环的设计:http://www.751com.cn/tongxin/lunwen_8519.html