Huawei EM820W manual Antenna Design Requirements, Antenna Design Indicators

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HUAWEI EM820W HSPA+ PC Embedded Module

 

Hardware Guide

RF Specifications

4.4 Antenna Design Requirements

4.4.1 Antenna Design Indicators

Antenna Efficiency

Antenna efficiency is the ratio of the input power to the radiated or received power of an antenna. The radiated power of an antenna is always lower than the input power due to the following losses: return loss, material loss, and coupling loss. The efficiency of an antenna relates to its electrical dimensions. To be specific, the antenna efficiency increases with the electrical dimensions. In addition, the transmission cable from the antenna port of the EM820W to the antenna is also part of the antenna. The cable loss increases with the cable length and the frequency. It is recommended that the cable loss should be as low as possible, for example, U.FL- LP-088 made by HRS.

The following antenna efficiency (free space) is recommended for the EM820W on a laptop to ensure high radio performance of the EM820W:

zEfficiency of the master antenna > 40% (-4 dB)

zEfficiency of the slave antenna > 40% (-4 dB)

zEfficiency of the GPS antenna > 50% (-3 dB)

zEfficiency of the Wi-Fi antenna > 40% (-4 dB)

Isolation

For a wireless device with multiple antennas, the power of different antennas is coupled with each other. Antenna isolation is used to measure the power coupling. The power radiated by an antenna might be received by an adjacent antenna, which decreases the antenna radiation efficiency and affects the running of other devices. To avoid this problem, evaluate the antenna isolation as sufficiently as possible at the early stage of antenna design.

Antenna isolation depends on the following factors:

zDistance between antennas

zAntenna type

zAntenna direction

The master antenna must be placed as near as possible to the EM820W to minimize the cable length. The slave antenna needs to be installed perpendicularly to the master antenna. The slave antenna can be placed farther away from the EM820W. Antenna isolation can be measured with a two-port vector network analyzer.

The following antenna isolation is recommended for the antennas on laptops:

zIsolation between master and slave antennas < -12 dB

zIsolation between the master antenna and the GPS antenna < -15 dB

zIsolation between the slave antenna and the Wi-Fi antenna < -15 dB

If a Wi-Fi module is installed on the laptop, the following measures must be taken to reduce mutual influence between the data card module and the Wi-Fi module:

Issue 01 (2010-12-31)

Huawei Proprietary and Confidential

20

Copyright © Huawei Technologies Co., Ltd.

 

 

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Contents Hardware Guide Issue DateNo Warranty About This Document HistoryVersion Date Chapter Descriptions Contents Recommendations for Designing the Module Antennas Electrical and Reliability FeaturesTables Figures Overview IntroductionFunction Overview Feature DescriptionOverall Description About This ChapterSMS Circuit Block Diagram1Circuit block diagram of the EM820W module Application Block DiagramMini PCI Express Interface Description of the Application InterfacesCOEX1 UimresetWDISABLE# Wdisablen VCC3V3Mini Card ground Not connected USB signal D Input/outputUSB signal D+ Input/output Active-low LED signal Output Indicating the state CardVCC Power Sources and GroundsPower Supply Time Sequence Name Pins Minimum Type MaximumName Pin Description Direction to Module USB SignalsParameter Remarks TimeNominal value UnitUIM/SIM Usim SignalsUsim Interface Schematic Reference Pin Name DescriptionDesign Guide 7Vcc Minimum Maximum2Vcc 7Vcc SIM CLK requirementsVcc Vcc+0.3 Certification Test8SIM IO requirements VccSW Control Setting Radio Operation WDISABLE# SignalLEDWWAN# Signal Pins Name Description Direction to ModuleIF*R+VF+IF*100 =VCC 11LEDWWAN signalPins Name Description Additional Direction to Module LedwwanWakenbn Signal NC PinsNC pins are not internally connected in the EM820W Test Environment RF SpecificationsOperating Frequencies Conducted RF MeasurementEM820W Test Value dBm Conducted Rx Sensitivity and Tx PowerTest Standards Conducted Receive Sensitivity3GPP Protocol EM820W Test Value dBm Claim dBm Min Type Max Conducted Transmit PowerAntenna Design Requirements Antenna Design IndicatorsPCS UMTS850UMTS900 DCSEnvelope Correlation Coefficient Interference 3 GSM/WCDMA Antenna RequirementsGSM/WCDMA Antenna Requirements Passive Tests Radio Test EnvironmentRecommendations for Designing the Module Antennas Design RecommendationsESD Protection for the Antenna Interface Issue 01 Huawei Proprietary and Confidential Electrical and Reliability Features Working and Storage Temperatures and HumidityExtreme Working Conditions Specification Minimum Value Maximum Value Unit Electrical Criteria of Application InterfacesParameter Description Minimum Value Power Voltage Tolerance Peak Maximum Normal Maximum Power Supply FeaturesPower Supply Power ConsumptionDescription Test Value Units ConfigurationHsdpa Hsupa250 Up/1 Down 351 488 165 217 293 225 Up/1 DownGPRS900 EDGE850Reliability Features Scenario Idle Suspend Unit Offline Enabled DisabledTest Condition Standard Test Condition Standard EMC and ESD Features Dimensions and Interfaces of EM820W Mechanical SpecificationsDimensions and Interfaces Dimensions of the Mini PCI Express ConnectorInstalling the EM820W on the Main Board of PC Specification Selection for FastenersIssue 01 Huawei Proprietary and Confidential Romoving the EM820W from the Main Board of PC 1Circuits of typical interfaces in the EM820W module Appendix a Circuits of Typical InterfacesAcronym or Abbreviation Expansion Appendix B Acronyms and AbbreviationsPDU NTCPbcch PCB

EM820W specifications

The Huawei EM820W is a cutting-edge mobile broadband device that exemplifies Huawei's commitment to innovation and excellence in the telecommunications sector. Designed for seamless connectivity, the EM820W caters primarily to users who demand high-speed data access while on the move.

One of the standout features of the Huawei EM820W is its support for high-speed 4G LTE connectivity. With download speeds that can reach up to 150 Mbps and upload speeds of up to 50 Mbps, users can enjoy smooth streaming, rapid downloads, and responsive online gaming experiences. This capability makes the device an ideal choice for both individual users and business professionals who rely on robust internet access.

The EM820W is equipped with a compact and lightweight design, making it highly portable. This device can be easily carried in a pocket or bag, allowing users to stay connected wherever they go. Its plug-and-play feature simplifies the setup process, ensuring that even those who are not tech-savvy can easily get online.

Another notable aspect of the Huawei EM820W is its compatibility with a wide range of operating systems, including Windows, macOS, and various distributions of Linux. This versatility means that users can connect the device to their preferred platforms without facing compatibility issues, enhancing the overall user experience.

The device also incorporates advanced security features to safeguard user data, including built-in encryption protocols. This is particularly important for business users who require secure connections for sensitive transactions and communications.

In addition to its connectivity capabilities, the EM820W showcases energy-efficient technologies that optimize battery performance. The device is designed to consume minimal power, allowing users to prolong usage times without frequently recharging.

The Huawei EM820W comes with a user-friendly interface, enabling users to easily manage their connections and monitor data usage. This feature is valuable for those who need to track their internet consumption to avoid exceeding data limits imposed by service providers.

With its blend of speed, portability, and user-oriented features, the Huawei EM820W stands out as a reliable solution for those seeking robust mobile broadband capabilities. Whether for personal use or professional needs, this device ensures that users remain connected in an increasingly digital world.
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