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Huawei EM820W manual ESD Protection for the Antenna Interface

Models: EM820W

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HUAWEI EM820W HSPA+ PC Embedded Module
Hardware Guide	RF Specifications

Figure 4-2Recommended antenna positions

zIt is recommended that the antenna pattern be designed based on the horizontal polarized omnidirectional pattern that facilitates the reception of strong signals especially in outdoor environments.

zBesides the module antennas, a laptop has other internal antennas, such as the WLAN antenna. Therefore, when designing the module antennas, the requirement on the isolation between module antennas and other laptop antennas should be considered. Ensure that proper distance is maintained between antennas if possible. To reduce the interference between antennas, it is recommended that an antenna is not designed close to another one.

zCarefully design the metallic components (such as the external frame of the metallic shell) in and near the antenna area by considering the effects on the antenna performance (such as whether the frequency offset of the antenna occurs and whether the antenna pattern is deformed).

4.6ESD Protection for the Antenna Interface

In practical application, pay attention to the ESD protection for the antenna interface of the EM820W module. Incorrect operation may result in permanent damage to the RF components.

	Issue 01 (2010-12-31)	Huawei Proprietary and Confidential	26
		Copyright © Huawei Technologies Co., Ltd.

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Huawei EM820W manual ESD Protection for the Antenna Interface

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 IntroductionOverall Description Feature DescriptionAbout This Chapter Function OverviewSMS Circuit Block Diagram1Circuit block diagram of the EM820W module Application Block DiagramMini PCI Express Interface Description of the Application InterfacesWDISABLE# Wdisablen UimresetVCC3V3 COEX1USB signal D+ Input/output USB signal D Input/outputActive-low LED signal Output Indicating the state Card Mini Card ground Not connectedPower Supply Time Sequence Power Sources and GroundsName Pins Minimum Type Maximum VCCParameter Remarks USB SignalsTimeNominal value Unit Name Pin Description Direction to ModuleUsim Interface Schematic Reference Usim SignalsPin Name Description UIM/SIMDesign Guide 2Vcc Minimum Maximum7Vcc SIM CLK requirements 7Vcc8SIM IO requirements Certification TestVcc Vcc Vcc+0.3LEDWWAN# Signal WDISABLE# SignalPins Name Description Direction to Module SW Control Setting Radio OperationPins Name Description Additional Direction to Module 11LEDWWAN signalLedwwan IF*R+VF+IF*100 =VCCWakenbn Signal NC PinsNC pins are not internally connected in the EM820W Operating Frequencies RF SpecificationsConducted RF Measurement Test EnvironmentTest Standards Conducted Rx Sensitivity and Tx PowerConducted Receive Sensitivity EM820W Test Value dBm3GPP Protocol EM820W Test Value dBm Claim dBm Min Type Max Conducted Transmit PowerAntenna Design Requirements Antenna Design IndicatorsUMTS900 UMTS850DCS PCSEnvelope 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 Supply Power Supply FeaturesPower Consumption Power Voltage Tolerance Peak Maximum Normal MaximumHsdpa ConfigurationHsupa Description Test Value UnitsGPRS900 225 Up/1 DownEDGE850 250 Up/1 Down 351 488 165 217 293Reliability Features Scenario Idle Suspend Unit Offline Enabled DisabledTest Condition Standard Test Condition Standard EMC and ESD Features Dimensions and Interfaces Mechanical SpecificationsDimensions of the Mini PCI Express Connector Dimensions and Interfaces of EM820WInstalling 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 AbbreviationsPbcch NTCPCB PDU