基于六端口技术的直接变频接收前端

【作者】 仝仲彬；

【导师】 杨涛；

【作者基本信息】 电子科技大学 ， 电磁场与微波技术， 2008， 硕士

【摘要】 六端口技术最初是用于微波测量中自动网络分析仪的设计。从上世纪90年代末,六端口技术在无线通信接收机方面受到了广泛的重视。基于六端口技术的直接变频接收机被证明是一种适用于可重构、重复编程、多频带、多标准的很有前途的接收机结构。本文的主要目的是分析研究六端口接收机的工作原理、校准原理及其变频过程,设计了Ka频段的基于六端口技术的直接变频接收前端。本文首先介绍了采用加性混频过程的六端口接收机理论,并且研究了六端口接收机的校准方法,校准过程将有助于提高六端口接收机的性能。我们还分析了六端口接收机中变频及解调过程的频谱特性。本文给出了一个六端口接收前端MIC电路的详细设计过程。在该接收前端中,六端口结电路由一个Wilkinson功分器和三个分支线耦合器构成,采用介电常数εr= 9.9、厚度H=0.254mm的陶瓷基片衬底,测试结果表明其在26GHz到30GHz适合应用于六端口接收机;四个检波电路则是采用MSS20,141B10D零偏低势垒检波二极管,制作在一个介电常数εr= 2.2、厚度H=0.254mm的RT5880软基片上。我们还采用OMMIC公司提供的0.18μm GaAs PHEMTs工艺ED02AH设计了一个Ka频段基于六端口技术的直接变频接收前端的MMIC芯片。该接收前端芯片采用的六端口结电路由一个Wilkinson功分器和三个Lange耦合器构成,仿真结果表明该六端口结电路在整个Ka频段都适合于六端口接收前端的应用;采用ED02AH提供的GM肖特基二极管设计了平方率检波电路,最后整个六端口接收前端芯片面积为2.5×3.5 mm 2。更多还原

【Abstract】 The original six-port technique applies only to alternative network analyzers. Since the late 1990s, the six-port technique has also been used for wireless communications receivers. And the receiver based on six-port is proved to be a very promising candidate to be a reconfigurable, reprogrammable, multi-band, multi-standard receiver front-end. The aim of this work is to research the six-port theoretical background, and design a Ka-band direct conversion receiver front-end based-on six-port.First, we introduce the six-port receiver theory using the additive mixing, and we study a very convenient calibration algorithm which can improve the performance of the six-port receiver. We also give an accurate mathematical description of the frequency conversion and demodulation process in six-port receivers.Next, we give details about our newly developed six-port receiver front-end including the power detectors. The six-port junction using a Wilkinson coupler and three branch line couplers is fabricated on a 0.254mm ceramic substrate, and the measurement results show that it is suitable for being used in a six-port receiver. The detectors using MSS20,141B10D zero biased low barrier Schottky diodes are on a 0.254mm RT5880.Finally, we present a six-port receiver front-end realized in monolithic microwave integrated circuit (MMIC) technology using OMMIC 0.18μm GaAs PHEMTs foundry named ED02AH. The circuit combines all the essential functions, namely the six-port junction and four GM Schottky diode detectors, and the size is 2.5×3.5 mm 2.更多还原