Huawei EM820W manual Envelope Correlation Coefficient

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HUAWEI EM820W HSPA+ PC Embedded Module

 

Hardware Guide

RF Specifications

Envelope Correlation Coefficient

The envelope correlation coefficient indicates the correlation between different antennas in a multi-antenna system (master antenna, diversity antenna, and MIMO antenna). The correlation coefficient shows the similarity of radiation patterns, that is, amplitude and phase, of the antennas. The ideal correlation coefficient of a diversity antenna system or a MIMO antenna system is 0. A small value of the envelope correlation coefficient between the master antenna and the slave antenna indicates a high diversity gain. The envelope correlation coefficient depends on the following factors:

zDistance between antennas

zAntenna type

zAntenna direction

The antenna correlation coefficient differs from the antenna isolation. Sufficient antenna isolation does not represent a satisfactory correlation coefficient. For this reason, the two indicators need to be evaluated separately.

For the antennas on laptops, the recommended envelope correlation coefficient between the master antenna and the diversity antenna is smaller than 0.5.

Radiation Pattern

The radiation pattern of an antenna reflects the radiation features of the antenna in the remote field region. The radiation pattern of an antenna describes the power or field strength of the radiated electromagnetic waves in various directions from the antenna. The power or field strength varies with the angular coordinates (θ and φ), but is independent of the radial coordinates.

The radiation pattern of half wave dipole antennas is the best option for wireless terminals. The radiation pattern of half wave dipole antennas is omnidirectional in the horizontal plane, and the incident waves of base stations are often in the horizontal plane. For this reason, the reception is optimal.

To improve the performance of diversity antennas, it is recommended that the radiation pattern of the slave antenna be complementary with that of the master antenna.

The following radiation patterns are recommended for the antennas on laptops:

zMaster antenna: omnidirectional

zSlave antenna: complementary with the radiation pattern of the master slave

zGPS antenna: omnidirectional

zWi-Fi antenna: omnidirectional

Gain and Directivity

The radiation pattern of an antenna represents the field strength of the radiated electromagnetic waves in all directions, but not the power density that the antenna radiates in the specific direction. The directivity of an antenna, however, measures the power density that the antenna radiates.

Gain, as another important parameter of antennas, correlates closely to the directivity. The gain of an antenna takes both the directivity and the efficiency of the antenna

Issue 01 (2010-12-31)

Huawei Proprietary and Confidential

22

Copyright © Huawei Technologies Co., Ltd.

 

 

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Contents Hardware Guide Issue DateNo Warranty Version Date Chapter Descriptions About This DocumentHistory 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 =VCCNC pins are not internally connected in the EM820W Wakenbn SignalNC Pins 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 GSM/WCDMA Antenna Requirements Interference3 GSM/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 Extreme Working Conditions Electrical and Reliability FeaturesWorking and Storage Temperatures and Humidity Parameter Description Minimum Value Specification Minimum Value Maximum Value UnitElectrical Criteria of Application Interfaces 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 293Test Condition Standard Reliability FeaturesScenario Idle Suspend Unit Offline Enabled Disabled 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

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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