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摘要混频器是现代雷达、电子对抗、制导武器、无线通信以及其他许多微波测量系统中至关重要的部件。为了提高接收机的增益和灵敏度，一般都需要把射频信号经过混频变为较低频率的中频信号来进行进一步的处理。混频器电路可以由二极管、晶体管或场效应管组成，混频实际上是一个频谱的线性搬移过程，就是将较高频率的输入射频信号经过非线性器件变换成较低频率的输出中频信号。 本文首先对微波混频器的工作原理和性能指标做了详细介绍。接下来提出四种不同结构的混频器，它们分别是单端混频器、单平衡混频器、双平衡混频器和双双平衡混频器。对他们的结构进行了简单介绍，并对他们的特点进行了对比。 接着，对微波混频器进行了仿真设计。首先设计了 3dB 定向耦合器、二极管的输入、输出阻抗匹配电路、两个二极管、输出带通滤波器。然后对混频器整体进行了仿真，测出了一些技术参数，大体符合项目的要求。 61010
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毕业论文 关键词：混频器 设计 仿真
Title S-band mixer Abstract Mixer is the modern radar, electronic countermeasures, guided weapons, wireless communications, and many other vital components in microwave measurement system. In order to improve the sensitivity and gain of the receiver, are generally need to rf signal after mixing into a low frequency of intermediate frequency signal for further processing. Mixer circuit can be composed of diodes, transistors, or field effect tube, mixing is actually a spectrum of the linear moving process, is the high frequency of input rf signal through a nonlinear device into the low frequency output of the intermediate frequency signal. This paper on the working principle and performance indexes of microwave mixer is introduced in detail. Then puts forward four kinds of different structure of the mixer, they respectively are single-ended mixer, single balanced mixer, double balanced mixer and both balanced mixer. Has carried on the simple introduction about the structure of their, and compares their characteristics. Next, has carried on the simulation to microwave mixer is designed. First 3 db directional coupler, the diode is designed input and output impedance matching circuit, two diodes, output bandpass filter. Then simulated for mixer as a whole, some technical parameters has been measured, in accord with the requirement of project.
Keywords ：The mixer design simulation
1绪论 . 1
1.1 课题的研究背景及意义 1
1.2 国内外发展动态 1
1.3 本文的主要工作 3
2 混频器的原理 4
2.1 肖特基势垒二极管的结构 .. 4
2.2 二极管的等效电路 .. 5
2.4本章小结 8
3 混频器的技术指标 . 8
3.1 噪声系数 8
3.2 变频损耗 . 10
3.3 动态范围 . 12
3.4 双频三阶交调与线性度 . 13
3.5 工作频率 . 14
3.6 隔离度 .. 15
3.7 本振功率与工作点 15
3.8 端口驻波比 16
3.9 本章小结 . 16
4 二极管微波混频器 .. 16
4.1 单端口混频器 .. 17
4.2 单平衡混频器 .. 18
4.3 双平衡混频器 .. 19
4.4 双双平衡混频器 . 20
4.5 本章小结 . 21
5 S波段混频器的 ADS仿真 . 22
5.1 混频器的技术指标 22