移动电话组件技术

由于半导体技术的大幅提高,现在移动电话的功能远远超越10年前的机型,而且体积与价格也大幅降低。现代手机中的硬件电路仍包含射频(RF)、基带以及功率管理等组件,新旧手机之间的差异体现在集成度和额外组件上,例如多媒体应用处理、相机、MMS、彩屏、FM收音机、MP3、游戏、GPS全球定位系统以及各种连网技术。随着移动电话     

Nine-band antenna system for mobile phones

A physically and electrically small system of antennas, installed at the top of a 'monoblock' or 'bar' phone, is presented. The antennas cover nine bands - five cellular bands, the GPS and Bluetooth/WiFi bands and two future mobile TV bands.     

Multiband internal antenna for mobile phones

A new internal antenna for multiband cellphones comprises a U-shaped elongated flat conductor featuring a closed meandered slot, a ground and a feed leg. A benchmark on a Motorola T192 handset is conducted to illustrate the operation of this structure - called a folded inverted conformal antenna showing significantly more radiating bandwidth than a conventional dual-band PIFA.     

All-digital PLL and transmitter for mobile phones

We present the first all-digital PLL and polar transmitter for mobile phones. They are part of a single-chip GSM/EDGE transceiver SoC fabricated in a 90 nm digital CMOS process. The circuits are architectured from the ground up to be compatible with digital deep-submicron CMOS processes and be readily integrateable with a digital baseband and application processor. To achieve this, we exploit the new paradigm of a deep-submicron CMOS process environment by leveraging on the fast switching times of MOS transistors, the fine lithography and the precise device matching, while avoiding problems related to the limited voltage headroom. The transmitter architecture is fully digital and utilizes the wideband direct frequency modulation capability of the all-digital PLL. The amplitude modulation is realized digitally by regulating the number of active NMOS transistor switches in accordance with the instantaneous amplitude. The conventional RF frequency synthesizer architecture, based on a voltage-controlled oscillator and phase/frequency detector and charge-pump combination, has been replaced with a digitally controlled oscillator and a time-to-digital converter. The transmitter performs GMSK modulation with less than 0.5/spl deg/ rms phase error, -165 dBc/Hz phase noise at 20 MHz offset, and 10 /spl mu/s settling time. The 8-PSK EDGE spectral mask is met with 1.2% EVM. The transmitter occupies 1.5 mm/sup 2/ and consumes 42 mA at 1.2 V supply while producing 6 dBm RF output power.     

Investigating text input methods for mobile phones

Human Computer Interaction is a primary factor in the success or failure of any device but if an objective view is taken of the current mobile phone market you would be forgiven for thinking usability was secondary to aesthetics. Many phone manufacturers modify the design of phones to be different than the competition and to target fashion trends, usually at the expense of usability and performance. There is a lack of awareness among many buyers of the usability of the device they are purchasing and the disposability of modern technology is an effect rather than a cause of this. Designing new text entry methods for mobile devices can be expensive and labour-intensive. The assessment and comparison of a new text entry method with current methods is a necessary part of the design process. The best way to do this is through an empirical evaluation. The aim of the paper is to establish which mobile phone text input method best suits the requirements of a select group of target users. This study used a diverse range of users to compare devices that are in everyday use by most of the adult population. The proliferation of the devices is as yet unmatched by the study of their application and the consideration of their user friendliness.     

Are mobile phones safe?

Driven in part by disturbing allegations, a new wave of research in the United States and elsewhere is exploring possible links between cell phone radiation and cancer. Brain cancer, the topic of this article, is not the only health concern, but it dominates public discussion. A substantial body now exists of pertinent scientific evidence. This article discusses EM fields and research on looking for a link between them and cancer. The results of animal studies are briefly outlined. The article discusses exposure limits to RF radiation     

基于光栅的手机多视点立体显示技术研究

研究了基于多视点立体视频处理系统的手机客户终端显示技术。针对现有的8视点光栅立体手机显示技术的缺陷,在原有8视点立体图像合成算法的基础上,研究视差原理及校正方法和视点配对原理,采用调整视点间视差和减少视点数两种解决方案,并提出将两种方案进行结合的方法。经实验验证,本文提出的两种方法在保证原有立体显示效果的基础上,大幅度提高了立体显示的舒适度。     

Statistics of measured body loss for mobile phones

The variation in body loss for different users of a cellular handset is investigated. Measurements involving 200 test users of mobile communications (GSM) handsets have been performed and statistics are presented for a handset with three types of antennas. Differences in the body loss of up to 10 dB have been observed between users, thus indicating that body loss measurements for handsets should include several test persons. Depending on the antenna type, 8-13 test persons are required to obtain an estimate of the mean body loss with a ±1 dB confidence interval at a 90% level     

下一代手机用电源管理芯片

10多年前,当第一代蜂窝电话出现时,采用了许多分立功率器件.第一代手机显得很笨重,高功耗使得待机时间和通话时间都很短.为了响应客户对外形更小,性能更高的无线电子设备不断增长的需求,工程师发展了许多先进的设计技术.这些技术既可缩小印刷电路板(PCB)尺寸,又可以提供更快更高效的性能.     

Design of an internal quad-band antenna for mobile phones

This letter presents the design of a compact Planar Inverted-F Antenna (PIFA) suitable for cellular telephone applications. The quarter-wavelength antenna combines the use of a slot, shorted parasitic patches and capacitive loads to achieve multiband operation. The commercial electromagnetic software IE3D is used to design and optimize the structure. The resulting antenna can operate from 880 to 960 MHz and 1710 to 2170 MHz covering GSM, DCS, PCS, and UMTS standards with a VSWR better than 2.5. Good agreement is found between simulated and measured results.     

The distributional effects of leapfrogging in mobile phones

This paper uses theory and empirical evidence to analyze the distributional effects of leapfrogging in mobile phones. The theory draws on earlier work on leapfrogging and Sen’s model of functionings and capabilities. The evidence draws partly on simple regression analysis. A key role is assigned to fixed-line telephony in reaching the conclusion that leapfrogging in mobile phones tends overall to be egalitarian in its impact on different developing countries. Mobiles however constitute very much the exception when it comes to technological relationships between rich and poor countries.     

行业安全手机探索研究

党政军、学校、企业等特殊行业主要移动互联网安全问题是接入设备安全、移动应用安全、用户接入认证安全等.本文将从操作系统安全、应用程序安全、设备管理安全、网络传输安全4个方面进行讨论,实行对手机的全面安全防护,为行业安全提供成套解决方案.     

八频段手机天线设计

提出了一种新颖的适应于手机终端上的八频段手机内置天线。利用（planar InvertedF antenna PIFA)天线原理、多带线设计方案,便于实现小型化及多频段的要求,同时分析了一些重要结构参量对天线性能的影响。仿真结果表明：该天线能够工作在八个常用的无线通讯服务频段,同时具有全向性方向图、增益和辐射效率高的特点,且每个工作频点及带宽可通过调节天线中带线的长度来获得。实际加工做了天线并测试,天线的测试结果表明与仿真结果具有较好的一致性。所设计的天线体积小、调整方便,可应用于无线通讯中的手机终端。     

用于3V GSM双频移动电话的功放解决方案

引言 随着蜂窝系统用户数量的暴涨,大都市地区的网络拥塞也就成为一个问题。为了增加网络的容量,运营商已经开始在不同的频率铺开新的网络。这个扩展的频率范围对用户来说必须是透明的,并且移动电话必须能够在多个频段内工作。本文专门讨论在ＧＳＭ手机上的功率放大器及其周边电路。ＧＳＭ系统在欧洲、亚洲和美国是使用最广泛的系统,在对发射电路及其涉及的设计问题作一般性讨论之后将介绍一种能使用在双频和三频ＧＳＭ手机的功放解决方案。 最初分配给ＧＳＭ移动电话（又称移动站）的发射频段是８９０ＭＨｚ到９１５ＭＨｚ。前几年,当…     

在移动电话中的接收和发射FM信号的内置天线

问题的提出 这几年来,多数移动电话中都使用了无线调频(FM)信号接收组件.由于波长长(λ～3 m),占调频频带较大(带宽是FM调频频带76～108 MHz的35%),免提耳机的连接线常被当作天线使用,而电话的底板(也许还有使用者)则当作地线,于是在收听时需要连接免提耳机.     

Evaluation of radiation exposure by UMTS mobile phones

An overview of the radiated power by a UMTS mobile phone in everyday usage is given. Compared to GSM, the exposure is presently about a thousandfold lower in comparable situations. Both location and time dependence as well as the control of the output power have been investigated using operating networks in Germany.     

LMS-based calibration of an RF digitally controlled oscillator for mobile phones

We propose a least-mean square based gain calibration technique of an RF digitally controlled oscillator (DCO) in an all-digital phase-locked loop (ADPLL). The DCO gain of about 12-kHz/least significant bit is subject to process, voltage and temperature variations, but is tracked and compensated in real time. Precise setting of the inverse DCO gain in the ADPLL modulating path allows direct wide-band frequency modulation that is independent from the ADPLL loop bandwidth. The technique is part of a single-chip fully compliant Global System for Mobile Communications (GSM)/EDGE transceiver in 90-nm digital CMOS.     

The Queen of SIMs [mobile phones]

The SIM (Subscriber Identity Module) transformed the smartcard business as mobile phones started to flourish and each had to carry one. But, as the networks become increasingly complex, offering a multiplicity of capabilities to the users-multimedia applications, high-performance processing, large storage and commerce-the complexity of the SIM grows, too. The USIM (Universal Subscriber Identity Module) will improve the relationship with the users and it's a good candidate to enable content delivery. The USIM is expected to offer higher capacities, going into the megabyte domain, to be able to store even more data to meet the growing number of applications in its pitch to be 'all things to all people'.     

手机TV技术闪亮登场

随着通信技术的不断发展，手机的功能越来越多。当前在手机市场已经出现了具有超高像素的拍照手机、整合MP3功能的音乐手机、集多种功能于一身的高级智能手机、可以随时随地收看电视节目的视频手机等。特别是电视视频手机(本文以下称“手机TV”）．将会把终端市场打造得更为精彩，给消费者带来更加丰富的信息内容，颇受业界青睐。