Ka波段250W连续波行波管的研制

本文介绍了一种Ka波段连续波250W螺旋线行波管研制的主要技术方案。介绍了这种行波管的研究现状和研制成果。     

基于Ka频段的自适应MIMO调制算法

这里研究了一种应用于Ka频段卫星通信信道的自适应多输入多输出(MIMO,multiple-Input multiple-Out-put)调制算法,不同于一般Ka频段卫星通信的信道衰减补偿算法,该算法主要是能根据不同天气条件,利用MIMO系统的接收信噪比自适应的转换调制方式,以维持一定的目标比特率为目标,从而获取较高的系统吞吐量。仿真结果表明,该算法能有效应对Ka频段固定卫星通信信道下的严重信道衰落,兼顾系统性能和频谱效率,得到较高的吞吐量。     

基于加载线型Ka频段的五位数字移相器

数字移相器广泛应用于相控阵雷达中,本文采用一前一后加载支线的方法设计了 11.25°,22.5°和45°移相单元,以3 dB支线耦合器的形式设计90°和180°移相单元,在Ka频段研制出五位数字移相器。该移相器在30 GHz~31 GHz工作频带内,各移相单元实测相移误差最大为6.5°,最小为0.2°;插入损耗最大为11.8 dB,最小为8.6 dB;输入驻波比小于2,整个电路尺寸为110 mm×55 mm×25 mm。     

Ka频段下变频模块设计

介绍了Ka频段下变频模块的设计。该模块的功能是将接收到的19.2~21.2GHz射频信号下变频到2.2~4.2GHz的中频信号。实际制作的下变频模块变频增益为20dB±1 dB,噪声系数小于6dB,镜频抑制大于100dB。该模块在Ka频段卫星通信系统中有着广阔的应用前景。试验结果证明,微波CAD工具的应用不仅降低了产品的研制成本,而且缩短了产品从电路设计到批量生产的时间。     

System concept for a digital repeater intended for a future generation of german telecommunication satellites

The derivation of a system concept for the digital multi-service repeater starts from evaluating the mission profile and the antenna concept elaborated so far. Furthermore, the repeater concept is shaped by Ka-band propagation conditions, the kind of integration of a down-link TV-distribution service into the prevailing multi-beam communications mode and readily available digital technologies. It is intended to embark on a completely regenerative approach using a unified switching concept for all services accompanied by a large amount of rearrangement functions in the foreground. An attempt is made to define those network control functions and procedures to be located on-board exploiting the fact that the repeater already acts as a central switching node. The discussion of on-board digital technologies concentrates upon a multicarrier demodulator concept and a candidate solution for the baseband switch. One general boundary condition is pronounced due to uncertainties about the actual traffic scenario in the future: all repeater resources must be accessible for the most important of the services considered, i.e. the provision of satellite business services.     

ACTS MOBILE TERMINALS

The development of the advanced communications technology satellite (ACTS) mobile terminal (AMT) and its follow-on, the broadband aeronautical terminal (BAT), have provided an excellent testbed for the evaluation of K- and Ka-band mobile satellite communications systems. Such systems have proved viable for many different commercial and government applications. Combining emerging satellite communications technologies such as ACTS' highly focused spotbeams with the smaller, higher-gain K- and Ka-band antenna technology, results in system designs that can support significantly higher throughput capacity than today's current commercial systems. An overview of both of these terminals is presented in this paper.     

高性能Ka频段收发前端的研制

介绍了一种Ka频段收发前端的工作原理和工程研制结果。该收发前端采用四次谐波混频器、毫米波微带滤波器、多芯片混合集成等技术,具有高性能、小型化、高可靠性等优点,并在宽温度范围、振动、冲击等条件下,满足毫米波系统要求。     

Ka频段高载波抑制的2阶直接调制器研究

介绍了一种基于载波2 阶谐波分量进行相位调制的毫米波直接调制器的研究工作。毫米波正交调制器由于其载波泄漏而无法满足工程应用低误码率的传输需求。针对该问题,设计反并联二极管对构建了毫米波正交乘法器,使基带信号与载波的2 阶谐波分量进行正交乘法运算,而落在调制信号带内载波的2阶分量在二极管对内部流动,对外无输出,提高了毫米波直接调制器的载波抑制度。同时载波工作频率变为原来的1/2,载波基波信号可以采用滤波器得到很高的抑制,并提高了电路的容错性。最终实现毫米波直接调制器的载波泄漏臆-50 dBm,经试验证明Ka频段2阶直接调制器的调制信号的码速率最高2.4 Gbit/s,可满足BPSK、QPSK、8PSK 等多种调制方式。     

A Ka-band low-noise amplifier with a coplanar waveguide (CPW) structure with 0.15-μm GaAs pHEMT technology

This investigation explores a low-noise amplifier (LNA) with a coplanar waveguide (CPW) structure, in which a two-stage amplifier is associated with a cascade schematic circuit, implemented in 0.15-μm GaAs pseudo-morphic high electron mobility transistor (pHEMT) technology in a Ka-band (26.5-40.0 GHz) microwave monolithic integrated circuit (MMIC). The experimental results demonstrate that the proposed LNA has a peak gain of 12.53 dB at 30 GHz and a minimum noise figure of 3.3 dB at 29.5 GHz, when biased at a V_(ds) of 2 V and a V_(gs) of-0.6 V with a drain current of 16 mA in the circuit. The results show that the millimeter-wave LNA with coplanar waveguide structure has a higher gain and wider bandwidth than a conventional circuit. Finally, the overall LNA characterization exhibits high gain and low noise, indicating that the LNA has a compact circuit and favorable RF characteristics. The strong RF character exhibited by the LNA circuit can be used in millimeter-wave circuit applications.     

一种新型小型化Ka波段波导带通滤波器的研制

设计了一种新型的小型化Ka波段波导带通滤波器。为了增加滤波器的带外抑制能力,在波导带通滤波器中设计插入了一个销钉。通过分析波导中销钉的等效电路,对加入销钉的滤波器进行了电磁场仿真设计。仿真结果表明,插入销钉的滤波器在高端引入了一个传输零点。按照仿真结果设计制作了波导带通滤波器,测试结果表明,该结构在保证性能指标的基础上有效的减小了波导滤波器的尺寸。该滤波器具有插入损耗低、零点位置调配灵活、体积小等优点。