The future generations of mobile communications based on broadband access technologies

The forthcoming mobile communication systems are expected to provide a wide variety of services, from high-quality voice to high-definition videos, through high data rate wireless channels anywhere in the world. The high data rate requires broad frequency bands, and sufficient broadband can be achieved in higher frequency bands such as microwave, Ka-band, and millimeter-wave. Broadband wireless channels have to be connected to broadband fixed networks such as the Internet and local area networks. The future-generation systems will include not only cellular phones, but also many new types of communication systems such as broadband wireless access systems, millimeter-wave LANs, intelligent transport systems, and high altitude stratospheric platform station systems. Key to the future generations of mobile communications are multimedia communications, wireless access to broadband fixed networks, and seamless roaming among different systems. This article discusses future-generation mobile communication systems.     

一种优异温度稳定性Ka波段上变频放大模块

研究了Ka波段变频放大电路的设计及其温度补偿技术,分析了上变频放大模块的基本原理,分别对射频增益及检波电压进行了温度补偿,提出了一种优异温度稳定性、高线性度、高增益稳定性的总体设计方案。该变频放大模块由放大电路、温补电路、混频电路、滤波电路及功率放大器等单元电路组成。运用Agilent ADS软件完成了模块的整体电路设计。同时,介绍了一种基于场仿真软件和实测相结合的方法,建立毫米波多芯片组件中互连的键合线模型,将键合线的寄生电感融入了上变频放大模块电路设计中,显著提高键合线互连电路的频率响应。采用多芯片组装工艺制作了高性能的变频放大模块,实现了在Ka波段输出功率＞于30.6 dBm,全温范围功率波动＜0.8 dB,全温检波电压指示波动＜0.2 V,测试结果与仿真结果一致。     

基于BCB的薄膜多层基板在毫米波T/R组件中的应用

基于BCB的薄膜多层基板具有优异的高频特性,是毫米波频段多芯片组件集成封装的重要途径。研究了BCB薄膜多层基板在Ka波段相控阵雷达T/R组件中应用的可行性,首先与LTCC基板对比验证了BCB微带线的传输特性,然后研制了功率分配/合成器、穿墙过渡等关键微波无源电路,最后设计了八通道的无源组件进行微波性能测试评估,结果表明基于BCB的薄膜多层基板能够满足应用需要。     

Performance Characterization of Wireless Multimedia through Heterogeneous Terrestrial-Satellite Network

In this work the transmission of multimedia services through heterogeneous integrated terrestrial-satellite networks is analyzed by means of measurement on a real test-bed including a video on demand (VoD) server, an IEEE802.11 wireless local area network (WLAN) integrated with a wired LAN, and a geostationary Ka-band satellite link in service at the Telecommunication Laboratory at IEIIT-BO/CNR, University of Bologna, Bologna, Italy. At first the WLAN radio link is characterized in terms of the mean received power level for different terminal locations within the Lab. Secondary, MPEG-1 video streams are transmitted with different data-rate from the VoD server to many wireless stations and the traffic, for both the single source and the aggregated traffic, is characterized. An integrated terrestrial-satellite LAN is simulated as an example of utilizationof source characterization. Moreover, the quality of service in terms of the average dropped MPEGframes-to-transmitted frames ratio is measured for different channel conditions, data-rate, and the number of wireless terminals requiring the service. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于LTCC 厚薄膜混合基板的Ka 波段T/ R 组件封装技术

收发组件的集成封装技术是毫米波二维有源相控阵领域应用研究的重点和难点。文中采用基于低温共烧陶瓷厚薄膜混合基板制造工艺技术,同时结合先进的微组装工艺,实现了Ka 波段八单元组件的高精度、高密度及气密封装;给出了收发组件的封装模型,通过仿真与实测对比着重分析了垂直互联、功率分配/ 合成网路及通道隔离的提升等关键技术,并测试了无源组件的微波性能。结果表明:该集成封装技术能够满足二维毫米波相控阵天线对T/ R 组件小型轻量化和高组装密度的技术要求。     

Ka-band Earth-space propagation research in Japan

Earth-space propagation studies in Japan were originally concerned with measuring atmospheric absorption and rain attenuation by means of a suntracker and a radiometer, following which a number of long-term experiments were performed using various experimental and commercial satellites. The first experiments involving Ka-band Earth-space propagation measurements in Japan were carried out in 1977 using the Engineering Test Satellite Type II, and since 1978, these experiments have been conducted using Japan's domestic communication satellite. Based on these studies to date, the understanding of Earth-space propagation characteristics at higher frequency bands, modeling of propagation channels, and development of countermeasure technologies have shown dramatic progress. In Japan at present, advanced propagation studies are under way in wideband digital-transmission satellite systems for the forthcoming multimedia era. This paper summarizes recent study activities concerning wave propagation in Ka-band Earth-space paths and related topics, such as radiometeorology in Japan. Last, future plans for conducting Ka-band and millimeter-wave propagation experiments by using the Japanese experimental satellite “COMETS” and rain observations in tropical regions by “TRMM” are introduced briefly     

A 60-GHz point-to-multipoint millimeter-wave fiber-radio communication system

A 60-GHz point-to-multipoint wireless access link with data rate of 156 Mb/s incorporating 60-GHz transceiver modules and full-duplex fiber-optic millimeter-wave transmission is developed for short-range applications such as indoor wireless local area networks and intelligent transport systems. For compact system configuration, a small-size millimeter-wave transceiver module with planar antennas is developed. The transceiver module is based on broadband planar integration and packaging of millimeter-wave circuits. The RF output power is +10 dBm and the measured 3-dB antenna beamwidth is 30/spl deg/. The total size of the developed 60-GHz transceiver module, except input and output connectors, is 50 mm /spl times/ 75 mm /spl times/ 35 mm. A point-to-point full duplex fiber-optic configuration is extended to the scheme with multiple access points (APs) by using a tree coupler and a dense wavelength division multiplexing multiplexer. The AP has a simple configuration without frequency conversion. The bit error rate and packet error rate performances of the 60-GHz fiber-radio access link are evaluated. Furthermore, the effect of the extension to the scheme with multiple APs is investigated.     

On-wafer characterization of millimeter-wave antennas for wirelessapplications

This paper demonstrates a deembedding technique and a direct on-substrate measurement technique for fast and inexpensive characterization of miniature antennas for wireless applications at millimeter-wave frequencies. The technique is demonstrated by measurements on a tapered slot antenna (TSA). The measured results at Ka-band frequencies include input impedance, mutual coupling between two TSA's, and absolute gain of TSA     

X/Ka频段遥感卫星地面接收信道便携式测试系统设计

为解决X/Ka信道在建设和运行维护过程中测试设备笨重、功能单一、设备操作复杂、工作状态无法获取等弊端,通过优化中频与射频链路方案、小型化与多功能集成设计、集中监控与射频线缆供电等方式,设计了一种便携式X/Ka频段遥感卫星接收信道测试系统,实现了1 GHz宽带X/Ka卫星数据地面接收系统射频(7.9~8.9 GHz、18~20 GHz、25~27.5 GHz 3个频段,有线或无线)、中频环路的调试和测试(1.2 GHz、1.5 GHz 2个频段)及信道的测试系统的集中监控、高阶调制、多种编码、多普勒仿真、噪声源添加等功能,极大地方便了现场或野外测试应用。     

A millimeter wave broadband wireless access technology demonstratorfor the next generation Internet network reach extension

We report design and implementation scenarios for a gigabit-capacity and high-data-rate fixed wireless access technology demonstrator. The system is based on a broadband wireless access concept and implementation techniques utilizing millimeter-wave and newly introduced free-space optical wireless high-speed links. The demonstration platform is to provide broadband “last mile” access and networking solutions to Internet users in densely populated areas with homes and businesses (e.g., building-centric and inner city environments) in need of high bandwidth not served by the fiber infrastructure. The investigation focuses on the radio link design, network architecture, system integration, and a compatible interface to the existing ATM fiber and satellite core networks in support of the next-generation Internet (NGI) reach network extension by the wireless technology     

Development of Millimeter-Wave Radio-over-Fiber Technology

Millimeter-wave radio-over-fiber technology demonstrates the potential for providing wireless broad-band service in the next generation wireless communication system.Optical generation of millimeter-wave signal is one of the most important technologies of millimeter-wave radio-over-fiber system.The virtues and shortcomings of some ways of optical generation of millimeter-wave signal are discussed.Then optical millimeter-wave signal transmission performance is described.Finally,an overview of the millimeter-wave radio-over-fiber system is given.It is suggested that the millimeter-wave radio-over-fiber technology should be paid more attention,especially for modulators for optical generation of millimeter-wave signal and radio-over-fiber system.     

K-band and millimeter-wave MMICs for emerging commercial wirelessapplications

The recent K-band monolithic-microwave integrated-circuit (MMIC) technologies for the local multipoint distribution service systems and novel MMIC technologies for potential low-cost millimeter-wave MMICs are presented in this paper via a review of Fujitsu Quantum Devices Limited technology. The devices being demonstrated are a 23-26-GHz 2-W power amplifier module with a broad-band driver amplifier, a 19-33-GHz miniature low-noise amplifier, a frequency multiplier by four for K-band local oscillators, a flip-chip MMIC module for radar application, and three-dimensional MMIC image-rejection harmonic mixers. Through these devices, the recent trend of design and fabrication methodologies for the K-band and millimeter-wave devices will be described     

The Future Generations of Mobile Communications Based on Broadband Access Methods

The forthcoming mobile communication systems are expected to provide much variety of services from high quality voice to high definition videos through high data rate wireless channels at anywhere in the world. High data rate requires broad frequency bands, and sufficient broadband can be achieved in higher frequency bands such as microwave, Ka-band and millimeter-wave. Broadband wireless channels have to be connected to broadband fixed networks such as the Internet and local area networks. The future generation systems will include not only cellular phones, but also many new types of communication systems such as broadband wireless access systems, millimeter-wave LAN, intelligent transport systems (ITS) and high altitude stratospheric platform station (HAPS) systems. The key words in the future generations of mobile communications are multimedia communications, wireless access to broadband fixed networks and seamless roaming among different systems. This article discusses the future generations mobile communication systems.     

一种小型化毫米波延时组件的实现

介绍了毫米波延时组件的设计难点,并提出了相应的解决方案。在此基础上,设计并实现了一种Ka波段集成七位延时与增益补偿功能的延时组件。根据实测结果,4GHz带宽内实现了幅度带内平坦度≤±1.0 dB,延时相位精度≤±10°,延时幅度精度≤±1.0 dB,相位非线性≤20°,驻波≤1.8。     

A Novel Method for High-Power Thermal Vacuum Testing of Satellite Payloads Using Pickup Horns

This paper presents the development of a novel method for high-power thermal vacuum (TVAC) testing of satellite payloads using pickup horns (PUH). It describes the design, manufacture, and qualification results for a Ku-band pickup horn, followed by high-power thermal vacuum test results of a Ku-band satellite for fixed satellite service. Based on the successful demonstration of this method, a generic pickup horn (GPUH) - with improved performance over a large bandwidth, covering 7.0 GHz to 21.0 GHz - was developed for testing of X-band, Ku-band, and Ka-band satellite payloads. Detailed design and qualification aspects of the generic pickup horn are addressed, including measured results. This method has been successfully employed for high-power thermal vacuum testing of three different satellites at Lockheed Martin Commercial Space Systems (LMCSS), and is the planned testing method for all future payloads.     

未来毫米波移动宽带通信系统探析

无线数据业务的爆炸式增长,对无线通信系统的网络容量提出了更高的要求,增加可用频谱资源是满足未来无线通信系统中网络容量需求的重要手段。本文分析对毫米波频带的信道特性、关键技术、链路预算、应用场景等方面进行分析,说明了毫米波频段在移动宽带通信系统中具有广阔的使用前景。     

11.25°毫米波数字移相器的设计

设计了一种Ka波段11.25°数字移相器。采用一前一后加载支线的方式,在Ka波段内研制出11.25°数字移相器。该移相器在30～31GHz工作频带内,驻波比小于1.65,插入损耗小于3dB,固定相移11.25°,相位精度达到±3°。     

低功耗无线动物神经信号采集模块设计

文中根据RF无线射频原理,提出了一个适用于小体型动物的纯模拟、低功耗的无线神经信号采集模块设计方案。相比于数模混合方案,纯模拟的实现方案具有尺寸小、功耗低以及结构简单等优势。整个采集模块可以分为模拟前端放大和无线数据传输两部分。通过选用低功耗、低噪声的仪表放大器INA333和运算放大器OPA333构成模拟前端放大电路的两级放大结构,降低了电路的功耗和尺寸。通过添加反馈电感实现的反馈增强效应降低了Colpitts振荡器功耗。采用三极管极间电容对振荡器进行FM调制构成纯模拟无线数据传输电路,使得采集模块具有小尺寸、低功耗以及无线数据传输的特点。电路仿真以及实验测试结果均表明,该模块可以完成动物神经信号的无线采集,具有一定的实用性。     

低噪声接收机模块

随着现代军事系统和民用领域的发展,对低噪声、低功耗接收机模块的需求量越来越大.本文从蜂窝移动、GPS、CDMA和卫星通信四个方面简单阐述了低噪声接收机模块在无线领域的应用.最后,介绍了低噪声接收机模块在军事领域的发展现状.     

基于Zigbee定位技术的无线呼叫系统设计与实现

呼叫系统被广泛应用在各种场合,针对呼叫系统中人员位置确定和呼叫处理等问题,设计出一套基于Zigbee定位技术的无线呼叫系统.该系统具有人员定位、呼叫处理和自动通知等功能,采用CC2530模块作为固定设备,CC2431模块作为移动设备,通过RSSI定位方法确定移动设备位置.由上位机软件处理呼叫命令,通过比较设备间距离选择与呼叫设备距离较近的服务设备,达到快速响应呼叫的目的.