Ka频段遥感卫星数据接收系统跟踪性能测试新方法

针对Ka频段低轨遥感卫星数据接收系统跟踪性能测试中的问题,提出了一种新的测试方法。利用设计的Ka频段低轨卫星动态目标模拟数据,采用转动第三轴跟踪标校塔Ka频段信标的方式模拟动态目标的跟踪,在研制的原型系统中开展了接收系统跟踪性能的测试验证。该测试方法可为Ka频段低轨卫星数据接收系统跟踪性能的测试验收提供参考。     

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。     

基于微波光子的宽带数据接收系统设计与验证

针对高速数据接收系统中传统电扫阵列瞬时带宽受限、数传速率难以进一步提升等问题,采用基于微波光子的“阵元移相+子阵真时延”光电协同多波束形成方法,利用光学真延时技术设计了Ka频段8通道二维扫描光电混合波束形成系统,通过稀疏设计进一步降低了系统复杂度。研制了单子阵64阵元规模的高速数据接收系统原理样机并进行了测试,结果表明在25.35～27.1 GHz工作频段无线信道条件下,阵列扫描范围为±40°,可同时形成8个波束;在QPSK数传体制下接收速率达1.5 Gb/s,误码率小于等于1×10^-7,误差矢量幅度(Error Vector Magnitude, EVM)指标优于3%。相关工作可为多波束和大带宽的高速数据接收设备等提供技术支撑与参考。     

基于介质波导混合模式的双频馈源喇叭天线

随着大型反射面天线技术的不断发展,天线系统对设备功能的多样化与一体化提出了更高的要求,馈源作为大型反射面天线的核心,其性能决定了反射面天线整体特性。文章基于介质波导混合模式提出了一种介质加载双频馈源喇叭天线,工作于X(7.25~7.75 GHz) / Ka(21~22 GHz)频段。利用特征值理论求解双层介质波导中电磁场表达式,通过改变双层介质波导拓扑结构,形成表面波态的混合模式HE₁₁。在X频段由于喇叭口径小,形成了E面H面等化的方向图;在Ka频段,通过改变介质锥形状,形成类似点源辐射,也形成了E面H面等化、交叉极化低的方向图。对该馈源进行加工并测试,测试方向图与仿真结果较为吻合。将该馈源应用于卫星地面接收系统的13 m环焦反射面天线,经验证,该天线在工作频段口面效率均≥60%。     

Ka频段低噪声接收前端设计

介绍了一种应用于卫星通信的Ka频段低噪声接收前端的设计方法.通过合理选择器件组合和电路形式,优化输入连接和电路级间匹配,最终研制完成了Ka频段低噪声接收前端.接收前端的接收信号频率在30 GHz附近.在0.8 GHz工作带宽内,噪声系数小于2.2dB,增益大于60 dB,带内增益波动小于1 dB.3套样机的测试结果验证...     

三菱电气开发出Ka波段低噪声HEMT

三菱电气公司开发出一种高增益型X级微封装HEMT。该器件非常适用于18-20GHz频段卫星广播接收系统和甚小孔径终端(VSAT)系统中的低噪声放大器。上述产品主要用在Ka波段直播卫星与甚小孔径终端领域,用于接收变频器中的低噪声放大器。新近推出的20GHz(下行线路)/30GHz上行线路)(Ka     

采用次谐波混频技术的毫米波超宽带混频器研制

提出了一种次谐波混频技术结合宽带匹配滤波电路的设计方法,能有效降低本振源的制作难度,并可扩展中频带宽。应用高频场仿真软件以及谐波平衡仿真软件,研制了两个频段的超宽带次谐波混频器。测试结果:K频段混频器,固定本振频率15 GHz,射频频率在18~26.5 GHz的频带内变化时,变频损耗小于10.7 dB,最小变频损耗为7.5 dB;Ka频段混频器,固定本振频率22 GHz,射频频率在26.5~40 GHz的频带内变化时,变频损耗小于11.5 dB,最小变频损耗为8 dB。测试结果指标与传统的双平衡混频器指标相当,证明了电路设计方案的正确性。     

利用矩阵实现气象卫星信号的可靠接收

矩阵是一种可一进多出的电器设备,能实现信号的选择和扩展。在风云三号系列气象卫星地面数据接收系统链路中使用了射频矩阵、中频矩阵、数据矩阵后,使得原两套相互独立的数据接收链路在射频、中频、基带3个频点上有了纽带、联系和交换,从而在射频、中频、基带3个节点上实现灵活切换、灵活组配,大大提高了设备利用率,确保卫星信号不因链路中某台设备故障而中断,使卫星信号的接收、传输更加可靠。     

基于叠层SIW滤波器的高集成硅基毫米波收发前端

提出了一种基于硅基晶圆级封装技术的小型化Ka频段收发前端,实现了接收通道、发射通道与本振产生电路的一体集成。该收发前端采用嵌入叠层型基片集成波导(SIW)滤波器结构实现高选择性预选滤波与低损耗垂直互连过渡的一体化设计。测试结果表明,该Ka频段滤波器中心损耗1 dB,1 dB带宽4.02 GHz,中心频偏5 GHz处抑制度优于35 dB,仿真与测试结果吻合良好。在前端模组设计中,通过采用硅基微腔屏蔽实现紧凑尺寸下各功能单元的隔离,通过采用1/4波长短路传输线结构抑制电源、控制等低频信号对接收中频的干扰,最终实现了该毫米波收发前端的小型化集成,其尺寸仅为20 mm×20 mm×1.25 mm,主要电性能满足设计要求。     

多站时差定位数字接收机设计

针对多站时差定位接收系统探测精度和动态要求,文中设计一种基于确定性延迟的宽带接收机。硬件系统由基于GPS授时的确定性相位关系的时钟系统和宽带高速采集系统组成,实现300 MHz～18 GHz频段宽带信号的中频数字化接收和处理。同时,给出FPGA软件处理流程,采用信道化技术和数字视频检测技术实现对射频脉冲信号的截获和通道时间的测量。样机测试结果表明,接收机的最大瞬时带宽为200 MHz,瞬时动态超过66 dBc,综合动态大于78 dBc,延时随机误差小于100 ps,可满足多站时差定位接收系统的应用需求。     

An Ultra-Broadband Doubly Balanced Monolithic Ring Mixer for Ku- to Ka-band Applications

A novel 12-40 GHz ultra-broadband doubly balanced monolithic ring mixer with a small chip size covering the Ku- to Ka-band applications implemented by a 0.15-mum pseudo- morphic high electron-mobility transistor process is presented. The proposed mixer consists of two spiral transformer baluns and a band-reject filter. The use of the spiral baluns leads to the achievement of a chip size less than 0.8 times 0.8 mm². The radio frequency (RF) spiral balun with a band-reject filter served by an L-C resonator is used to improve the bandwidth of the mixer and to provide an output port for the intermediate frequency (IF) extraction as well. The mixer exhibits a 6-12 dB conversion loss, high isolation over 12-40 GHz RF/local oscillation bandwidth, a DC-8 GHz IF bandwidth, and a 1-dB compression power of 14 dBm for both down- and up-converter applications.     

Multi-band microwave photonic satellite repeater scheme employing intensity Mach-Zehnder modulators

To solve the satellite repeater's flexible and wideband frequency conversion problem, we propose a novel microwave photonic repeater system, which can convert the upload signal's carrier to six different frequencies. The scheme employs one 20 GHz bandwidth dual-drive Mach-Zehnder modulator (MZM) and two 10 GHz bandwidth MZMs. The basic principle of this scheme is filtering out two optical sidebands after the optical carrier suppression (OCS) modulation and combining two sidebands modulated by the input radio frequency (RF) signal. This structure can realize simultaneous multi-band frequency conversion with only one frequency-fixed microwave source and prevent generating harmful interference sidebands by using two corresponding optical filters after optical modulation. In the simulation, one C-band signal of 6 GHz carrier can be successfully converted to 12 GHz (Ku-band), 28 GHz, 34 GHz, 40 GHz, 46 GHz (Ka-band) and 52 GHz (V-band), which can be an attractive method to realize multi-band microwave photonic satellite repeater. Alternatively, the scheme can be configured to generate multi-band local oscillators (LOs) for widely satellite onboard clock distribution when the input RF signal is replaced by the internal clock source.     

Reconfigurable remote radio head design and implementation for super base station applications

This paper proposes a reconfigurable remote radio head (RRH) software and hardware architecture and presents the results of its implementation. The implemented RRH has been designed for a centralized architecture super base station that facilitates the integration of 2G, 3G, and 4G ground base stations and geosynchronous equatorial orbit (GEO) satellite gateway stations. The reconfigurable RRH is a primary aspect of the system. By modifying the programmable software configuration from the perspective of software-defined radio, the RRH can support multiple frequency allocations. The RRH is composed of radio frequency (RF) modules, intermediate frequency (IF) modules, and some of the physical layer functions. The development of a reconfigurable IF module is emphasized. A filter-bank multiplexing technique has been employed for the IF module, which reduces the use of hardware resources. To this end, we experimentally evaluated the main key performance indicators (KPIs) of the RRH. The experimental results demonstrate that the proposed design attains the goal of reducing hardware costs and improving system flexibility and stability.     

宽带低杂散LFM信号的产生方法与系统设计

针对宽带雷达线性调频信号产生,采用FPGA电路和宽带DAC电路直接产生50 MHz~550 MHz 的线性调频中频信号。将中频信号上变频到2 GHz~2. 5 GHz 的射频频段,再经过2 倍频获得4 GHz~5 GHz的宽频带线性调频信号。为进一步提高射频输出信号的幅度/相位特性,采用幅/相预失真校准方法,并精心设计信号产生系统的中频电路和射频电路,进行了实验研究与分析。对实际系统的测试结果表明,系统产生LFM信号的带外杂散优于-55 dB,带内起伏小于依2 dB,且系统稳定、可靠。     

甚高频(VHF)跳频电台接收模块的设计与实现

通过对甚高频(VHF)跳频电台射频前端接收模块设计指标和具体结构的介绍,对整个接收机射频前端电路进行了电路设计,构建了一个由第一、第二级混频器,中频放大器,第一、第二中频晶体滤波器,限幅器和推动器,正交检测器,收基带信号(RXBB)放大器,机内测试电路(BITE)以及静噪单音检测组成的接收模块电路。实验结果表明,所设计的接收模块的性能指标达到了系统设计要求,并有所提高。     

Monolithic SiGe Up‐/Down‐Conversion Mixers with Active Baluns

The purpose of this paper is to describe the implementation of monolithically matching circuits, interface circuits, and RF core circuits to the same substrate. We designed and fabricated on‐chip 1 to 6 GHz up‐conversion and 1 to 8 GHz down‐conversion mixers using a 0.8 µm SiGe hetero‐junction bipolar transistor (HBT) process technology. To fabricate a SiGe HBT, we used a reduced pressure chemical vapor deposition (RPCVD) system to grow a base epitaxial layer, and we adopted local oxidation of silicon (LOCOS) isolation to separate the device terminals. An up‐conversion mixer was implemented on‐chip using an intermediate frequency (IF) matching circuit, local oscillator (LO)/radio frequency (RF) wideband matching circuits, LO/IF input balun circuits, and an RF output balun circuit. The measured results of the fabricated up‐conversion mixer show a positive power conversion gain from 1 to 6 GHz and a bandwidth of about 4.5 GHz. Also, the down‐conversion mixer was implemented on‐chip using LO/RF wideband matching circuits, LO/RF input balun circuits, and an IF output balun circuit. The measured results of the fabricated down‐conversion mixer show a positive power conversion gain from 1 to 8 GHz and a bandwidth of about 4.5 GHz.     

Ka波段频率合成器

本文介绍了一种基于毫米波谐波混频、中频锁相的Ｋａ波段频率合成器的设计方案及实现结果。合成器的频率范围为２６．５￣４０ＧＨｚ,输出功率大于＋５ｄＢｍ,频率步进值为１ＭＨｚ,相噪指标为（１０ｋＨｚ）〈－６５ｄＢｃ／Ｈｚ,杂散低于－５５ｄＢｃ。     

Ka波段微带下变频器

下变频器简称高频头,是卫星电视接收系统的一个重要组成部分,它可对卫星下行信号进行放大和变频.与传统的C波段和Ku波段下变频器相比,Ka波段下变频器具有许多优点,正逐步在通信领域中得到应用.文中介绍了一种用于卫星直播系统的Ka波段微带下变频器,首先说明了其电路的工作原理和结构,然后研究了内部各模块的设计方法和用微波器件构造具体电路的实现过程.调试实验和实际接收表明该Ka波段下变频器具有良好的性能和较大的实用价值.