Electromagnetic interference on medical equipment by low-powermobile telecommunication systems

There have been a number of reports of electromagnetic interference (EMI) on electronic medical equipment caused by mobile telecommunication systems. In Japan, the use of the personal handy-phone system (PHS) has greatly expanded within urban areas, PHS handsets transmit EM signals at a frequency of 1.9 GHz and have a peak radiated power of 80 mW. This power level is lower than that of other mobile telecommunication systems. Two studies were carried out. One was to determine whether or not PHS interferes with electronic medical equipment in hospitals. We observed no EMI on electronic medical equipment when the PHS handset was in either the speaking mode or on standby. The second study was to observe EMI from 1.9-GHz signals at several radiation power levels. Although EMI was not observed at the radiated peak power of the PHS handset, EMI on some of the tested equipment was observed when the radiated power was ten or more times higher than that of the PHS handset     

Printed antennas for dual-band GSM/DCS 1800 mobile handsets

The recent developments of dual-band dual-mode D-AMPS/AMPS mobile handsets and radiostations has increased pressure on GSM service providers to follow similar technology breakthroughs as a first step towards IMT2000. A frequency-agile device accommodating both GSM standard frequency bands would serve more than 25 million GSM subscribers, with expectations as high as 100 million subscribers by the year 2000. Novel dual-band printed bow-tie antenna elements developed for dual-mode GSM/DCS 1800 handsets are described     

Integration spannungsabstimmbarer Oszillatoren für Mobilfunkanwendungen

The frequency concepts of GSM and DECT systems in mobile handsets consist mainly of three voltage controlled oscillators. The goal of this work is the integration of these oscillators with a bipolar technology. In this paper the requirements for the oscillators are shown. The possibilities of integration are examined theoretically and by experiment. For the GSM system a partly integrated solution is demonstrated and for the DECT system a fully integrated VCO is presented.     

iGSM: VoIP service for mobile networks

This article proposes iGSM: a voice-over-IP value-added service for the mobile network. The iGSM service provides user mobility to subscribers, which allows them to use either GSM handsets or H.323 terminals (IP phones or PCs) to access telecommunications services. We describe how the iGSM registration, deregistration, and call delivery procedures can be implemented without modifying the GSM network. We study how the tromboning effect in the standard GSM system can be avoided when accessing the IP network. Then we investigate the misrouting problem caused by user mobility     

室内单个UWB设备对GSM系统的干扰分析

根据FCC频谱模板,分析了室内单个UWB设备工作时的发射信号对GSM通信系统(包括GSM900和DCS1800)的电磁干扰;仿真了UWB设备和GSM移动台间距离对GSMMS接收信噪比的影响。其中UWB干扰信号对GSM900的干扰在信噪比冗余度内。而对DCS1800的干扰远大于GSM900,当二者距离小于25cm时,降到9dB以下,通信质量严重下降,链路会因此中断。     

iSMS: an integration platform for short message service and IPnetworks

This article describes iSMS, a platform that integrates IP networks with the short message service in mobile telephone systems. iSMS provides a generic gateway for creating and hosting wireless data services for mobile stations. Our approach does not require any modification to the mobile telephone system architecture. The iSMS system can be quickly developed and operated by a third party or end user without involvement of mobile equipment manufacturers and telecom operators. Based on the iSMS platform, we illustrate services such as e-mail delivery/forwarding, Web access (e.g., stock and train schedule query) and handset music services. The iSMS platform and the services have been implemented for GSM networks. With iSMS, users are able to use standard GSM handsets to access wireless Internet services, while other approaches like the Wireless Application Protocol and SIM Toolkit services require function-enabled MSs     

Design of a multiband internal antenna for third generation mobile phone handsets

A multiband internal antenna is introduced. The antenna consists of a driven meander-line element and two parasitic elements. The design is particularly unique since it supports the third generation mobile phone handsets where multiband operation is greatly desired. The proposed antenna operates effectively in the AMPS 800 (824-894 MHz), GSM 900 (880-960 MHz), and GSM 1900 (1850-1990 MHz) bands within 2.5:1 voltage standing wave ratio (VSWR). Detail design criteria with respect to geometrical parameter variation are given. Experimental data (VSWR and pattern) obtained from a laboratory prototype are also presented.     

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     

In-network performance of handheld mobile terminals

This paper considers a realistic evaluation of the power mobile handsets are able to transmit and receive. It has been suggested to use the so-called total radiated power (TRP) and the total isotropic sensitivity (TIS) for the uplink and downlink, respectively, which may be seen as special cases of the general mean-effective-gain (MEG) measure. These measures are computed from the spherical radiation pattern of the handset and the different measures are obtained by using different models of the mobile propagation environment. In this paper, the results obtained via the spherical radiation patterns are compared with the equivalent performance obtained in a live Global System for Mobile Communications (GSM) network using data from the Abis network interface. This method does not require altering of the handsets and the testing uses normal calls in the network. The investigation is based on measurements with four different commercially available handsets carried out in two different indoor environments and involving 22 test users. In addition, a series of measurements were also made with a phantom simulating the handset user, allowing a test of how well the phantom represents the average user.     

Electromagnetic fields radiated by GSM antennas

The increasing presence in many countries of base stations (BTSs) for mobile communications has caused, in recent years, growing anxiety among people living close to BTsS about the biological effects of electromagnetic pollution. A fast and efficient method is presented for evaluating the electromagnetic field levels radiated by GSM antennas.     

Potential GPRS 900/180-MHz and WCDMA 1900-MHz interference to medical devices

This study compared the potential for interference to medical devices from radio frequency (RF) fields radiated by GSM 900/1800-MHz, general packet radio service (GPRS) 900/1800-MHz, and wideband code division multiple access (WCDMA) 1900-MHz handsets. The study used a balanced half-wave dipole antenna, which was energized with a signal at the standard power level for each technology, and then brought towards the medical device while noting the distance at which interference became apparent. Additional testing was performed with signals that comply with the requirements of the international immunity standard to RF fields, IEC 61000-4-3. The testing provides a sense of the overall interference impact that GPRS and WCDMA (frequency division duplex) may have, relative to current mobile technologies, and to the internationally recognized standard for radiated RF immunity. Ten medical devices were tested: two pulse oximeters, a blood pressure monitor, a patient monitor, a humidifier, three models of cardiac defibrillator, and two models of infusion pump. Our conclusion from this and a related study on consumer devices is that WCDMA handsets are unlikely to be a significant interference threat to medical electronics at typical separation distances.     

1999年中国蜂窝移动通信及手机市场走向分析

中国移动电话数已跃居世界第三位，增长速度在部分城市妆近或开始超过普通固定电话。而在设备市场上，中国开发的ＧＳＭ产品正在取得突破性进展，开始了国外产品的角逐，手机市场尤其如此。此外，中国移动通信标准的选择正处于关键时刻，可能影响到第三代移动通信技术的选用。     

RADIO AND NETWORK COMPARISONS FOR MSBN AND GSM SYSTEMS IN A GEOSTATIONARY SATELLITE ENVIRONMENT

One of the most frequently debated issues in satellite communications concerns the comparison between time division multiple access (TDMA) and code division multiple access (CDMA) systems. Although, in our view, a general answer to this problem cannot be found, this paper presents comparisons of two systems utilizing the above-mentioned access techniques, both from a radio and a network point of view. In particular, the mobile satellite business network (MSBN), (a CDMA system currently being developed by the European Space Agency (ESA) for general satellite applications) and the full integrated extension to satellite systems of the global system for mobile communication (GSM) (the well-known frequency division multiplex (FDM)/TDMA pan-European mobile cellular system) are compared by taking, as the reference payload, the L-band land mobile (LLM) satellite (a spot-beam geostationary satellite whose launch should take place at the end of 1997). Reasonable assumptions take into account the fact that, on one hand, the MSBN system is not completely defined and, on the other, the GSM is applied in a context different from the one specified by the European Telecommunication Standard Institute (ETSI). Performance comparisons are carried out in terms of flexibility and number of available channels for the same quality requirements, emitted power levels, propagation environment and interference levels coming from adjacent satellites. It is concluded that MSBN is more flexible than GSM and that, as regards capacity, an advantage of GSM over MSBN is present in the transportable mobile case, whereas, in the vehicular mobile case, MSBN shows an advantage over GSM. © 1996 by John Wiley & Sons, Ltd.     

Planar meander sleeve monopole antenna for DVB-H/GSM mobile handsets

A novel planar meander sleeve monopole antenna for digital video broadcasting-hand held (DVB-H) and GSM mobile handsets is presented. By using the planar sleeve monopole type radiating element constructed with meander strips, the antenna provides a degree of miniaturisation while retaining a wide bandwidth covering the DVB-H and GSM-900 bands. A prototype is constructed and tested, which shows that an impedance bandwidth of 498 MHz (463-961 MHz) within 2.5:1 VSWR is achieved.     

Field-Line-Circuit Coupling Based Method for Predicting Radiated Electromagnetic Emission of IGBT-PMSM Drive System

Electric drive system with Insulated gate bipolar transistor (IGBT) power device is widely used in Electric vehicle (EV), which consists of inverter, cables and Permanent magnet synchronous motor (PMSM). Due to the fast switching in di/dt and dv/dt of IGBT device, the system produces serious radiated Electromagnetic interference (EMI) through the interconnection cables. Thus, modeling of EMI source, propagation path and load PMSM is the key to accurately evaluate the system's radiation level. In addition, the system's radiated EMI involves the integrated calculation of circuit, cable and electromagnetic field, which cannot be solved by using a single circuit or electromagnetic calculation method. Therefore, this paper develops an effective field-linecircuit coupling based method to investigate the radiated EMI problems for IGBT-PMSM drive system, which is validated by experimental measurement. Besides, the impact of power cable parameters on radiated EMI is discussed. The proposed approach has guiding significance for electromagnetic compatibility design of EV.     

A 2.7-V GSM RF transceiver IC

A 2.7-V RF transceiver IC is intended for small, low-cost global system for mobile communications (GSM) handsets. This chip includes a quadrature modulator (QMOD) and an offset phase locked loop (OPLL) in the transmit path and a dual IF receiver that consists of a low noise amplifier (LNA) with an active-bias circuit, two Gilbert-cell mixers, a programmable gain linear amplifier (PGA), and a quadrature demodulator (QDEM). The IC also contains frequency dividers with a very high frequency voltage controlled oscillator (VHF-VCO) to simplify the receiver design. The system evaluation results are the phase error of 2.7° r.m.s. and the noise transmitted in the GSM receiving band of -163 dBc/Hz for transmitters and the reference sensitivity of -105 dBm for receivers. Power-control functions are provided for independent transmit and receive operation. The IC is implemented by using bipolar technology with f_T=15 GHz, r'_bb=150 Ω, and 0.6-μm features     

Hepta-Band Internal Antenna for Personal Communication Handsets

Modern personal communication handsets are shrinking in size and are required to operate at multiple frequency bands for enhanced functionality and performance. This poses an important challenge for antenna designers to build multiband antennas within the limited allowable space. In this paper, an internal antenna covering seven frequency bands is presented for personal communication handsets. The proposed antenna operates at GSM (880-960 MHz), DCS (1710-1880 MHz), PCS (1880-1990 MHz), UMTS (1900-2170 MHz), WiBro (2300-2390 MHz), Bluetooth (2.4-2.48 GHz), and WLAN (5.0-5.5 GHz) frequency bands. Measured input return loss of the antenna is better than dB at all the frequency bands with reasonable radiation performance. Antenna volume is 30 mm times15 mm times 4.0 mm (1.8 cm) that makes it attractive for modern multiband and multifunctional slim handsets.     

A systematic coupled approach for electromagnetic susceptibility analysis of a shielded device with multilayer circuitry

This paper presents a systematic coupled approach for electromagnetic susceptibility (EMS) analysis of a shielded electronic device in the presence of an ambient electromagnetic interference (EMI). A full-wave electromagnetic modeling technique coupled with a circuit-based method is developed for the overall EMS performance analysis. The mixed-potential electric field integral equation (MPIE) is formulated via the method of moments to model the electromagnetic properties of an arbitrary structure consisting of wires and surfaces with any applied excitation. With numerical analysis, the effect of an ambient electromagnetic noise is characterized, and an equivalent circuit model is extracted for further analysis of EMI to internal high-speed sensitive circuits. Numerous examinations exhibit that this systematic coupled approach is a computationally efficient method to address the EMS problems at system level, in which the external EMI effects are fully considered and the circuit-based simulator is also exploited.     

多发射手机的FCC SAR测试技术要求

从工作频率、发射功率、天线间的距离、SAR分布等方面,阐述FCC对集成了多个同时发射的射频模块和天线的手机SAR测试技术要求,内容包括仅需进行单发射机模式SAR评估的条件、多发射模式的SAR测试判定原则和执行程序,以及头部模型的紧凑部位的替代测量方法等。     

Amplitude modulated RF fields stemming from a GSM/DCS‐1800 phone

Experiments which investigate possible effects arising from handheld phones employing amplitude modulated Radio Frequency (RF) fields, must deploy an excitation field which matches the true situation. Amplitude modulation arising from digital systems such as Global System for Mobile communication (GSM) or Digital Enhanced Cordless Telecommunications (DECT) is more complicated than just bursting of RF fields with a certain repetition rate and a certain duty cycle. In the GSM system the RF field is amplitude modulated with both a 217 Hz and an 8 Hz repetition rate. Furthermore, when the GSM land mobile network allows Discontinuous Transmission (DTX) the amplitude modulation rate can be as low as 2 Hz. Also the transmitted power may change in a complex manner. Extremely Low Frequency (ELF) magnetic fields connected with the current drawn from the battery of a handheld phone are investigated and measured, as a function of both time and frequency, and it is shown that the behavior of the current drawn is nearly the same as the one derived for the amplitude modulation of the RF power. This paper does not explain all details of the GSM system, but investigates the system in order to establish an experimental setup, which matches the real fields stemming from GSM mobile transmitters. For the purpose of comparison with digital cordless systems employing Time Division Multiple Access (TDMA) some figures of power and ELF magnetic field values are included.