节点文献
基于LTCC的超宽带毫米波收发前端
【作者】 沈大立；
【导师】 徐锐敏；
【作者基本信息】 电子科技大学 ， 电磁场与微波技术， 2010， 硕士
【摘要】 超宽带毫米波收发前端是毫米波电子战系统中的重要构成部分,低温共烧陶瓷(LTCC)技术给毫米波电子战系统向小型化、轻量化、高集成度方向的发展提供了有效的解决途径。本文从时分信道化理论出发,采用LTCC技术研究覆盖18-40GHz的收发前端,这在国内尚属首次,有着巨大的挑战性。本文在介绍LTCC基本特点和了解国内LTCC加工工艺水平的基础上研究了超宽带毫米波收发前端和其中的关键部件。本文从LTCC层间互连结构的集总电路模型出发,基于阻抗匹配理论研究了X波段的微带-带状线过渡,测得背靠背结构损耗小于1.4dB,回波损耗基本优于-10dB,可解决前端中布线交叉的问题;利用LTCC自身多层基板的优势,从平行耦合滤波器的设计理论出发,对传统结构进行了改进,研制出了两种新颖的毫米波LTCC宽带滤波器,插入损耗可分别小于3dB和2dB,带外4GHz处抑制度分别可达30dB和40dB;基于三线耦合滤波器设计理论研究了LTCC三线耦合滤波器,插入损耗小于2dB,带外4GHz处的抑制度优于30dB;基于耦合系数法和外部Qe值设计理论,采用了一种新颖的耦合抽头结构制作了X波段全频段LTCC滤波器,插入损耗小于1.5dB,可作为中频滤波器使用;基于时分信道化理论研究制作的毫米波LTCC五路开关滤波组件,带外抑制度较高,且性能最好的滤波通道损耗小于7.5dB。整个超宽带毫米波收发前端制作在一块10层Dupon943 LTCC介质基板上。腔体外形尺寸为108mm×80mm×18mm,重量小于220g。测试结果表明,接收增益在部分频率处大于20dB,最小噪声系数约为7dB。在未接末级功放情况下测得部分频率的发射功率大于-5dBm。
【Abstract】 As an important constitute of millimeter-wave electronic war (EW) sytem, ultra-wideband millimeter-wave transceiver front-end with miniaturization, low-weight, high integration can be implemented by LTCC technology. Based on Time Division Channel (TDC) technology, it is the first time to study the chanllenging 18-40GHz transceiver front-end in LTCC technology in China. This thesis introduces the basic features and technological level of LTCC in China and focuses on the research of ultra-wideband millimeter-wave transceiver front-end and its key components.First of all, based on lumped parameter model of interconnection between LTCC layers and impedance match theory,a microstrip-to-stripline transision in X-band is developed and perfomes well. Insertion loss is less than 1.4dB and return loss is better than -10dB of the back-to-back structure. It could be used to solve the cross wiring problem in the front-end. Second, from design method of parallel line coupled filter and based on the advantage of multi-layer LTCC substrates, traditional structure is modified and two new millimeter-wave wideband filters have been realized. Insertion loss is lower than 3dB and 2dB respectively. Stopband rejection could reach 30dB and 40dB at 4GHz away from passband respectively. Third, theory of three-line coupled filter is introduced. Insertion loss of the fabricated filter is less than 2dB and stopband rejection could reach 30dB at 4GHz away from passband. Last, based on coupling coefficient and external Qe value design theory, a full X-band band-pass filter is also achieved by using a new input and output coupled structure. Insertion loss is less than 1.5dB and it could be usd as IF filter. At the same time, based on Time Division Channel (TDC) theory, a millimeter-wave LTCC five channel switch-filter module with good stopband rejection is developed and insertion loss of the best channel is about 7.5dB.The whole ultra-wideband millimeter-wave transceiver front-end is fabricated in a ten-layer Dupont943 LTCC substrate. Dimension of the cavity is 108mm×80mm×18mm and its weight is lower than 220g. Test results show that receive gain at some frequency points is higher than 20dB and the smallest noise figure is about 7dB. Output power at some frequency points is higher than -5dB without the last power amplifier.