Co-Exsitence With 5 Ghz Wifi Design Guide; Purpose; Co-Exsitence Design Main Point - Huawei ME909u-521 Hardware Manual

HUAWEI ME909u-521 LTE LGA Module
Hardware Guide
Antenna Requirements
Bandwidth of
secondary antenna
Bandwidth of GPS
antenna
Gain
Impedance
VSWR absolute max
VSWR recommended

4.6 Co-exsitence with 5 GHz WIFI Design Guide

4.6.1 Purpose

ME909u-521 module supports LTE Band 1/Band 2/Band 3, GSM 1800 and GSM 1900,
and each of that band can generate the 2
GHz, so that will deteriorate 5 GHz WIFI receiver performance. That is why
Co-exsitence design needed.
Operating Band
Band 1 (UMTS, LTE)
Band 2 (UMTS, LTE), GSM1900
Band 3 (LTE), GSM1800

4.6.2 Co-exsitence Design Main Point

DC Power for ME909u-521 and WIFI Circuit
The suggest DC power tree is shown as below, use LC filter circuit for each branch.
Issue 05 (2017-12-15)
60 MHz in WCDMA/LTE Band 1
60 MHz in WCDMA/LTE Band 2
25 MHz in WCDMA/LTE Band 5
35 MHz in WCDMA/LTE Band 8
75 MHz in LTE Band 3
70 MHz in LTE Band 7
30 MHz in LTE Band 20
35 MHz in GNSS
≤ 2.5 dBi (≥ 3 dBi for GPS antenna)
50 Ω
≤ 3:1(≤ 2:1 for GPS antenna)
≤ 2:1(≤ 1.5:1 for GPS antenna)
Tx 2nd order
Frequency harmonic
range (MHz) Fre. Range
(MHz)
1920–1980 3840–3960
1850–1910 3700–3820
1710–1785 3420–3570
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nd rd
or 3 harmonic with the frequency about 5
3nd order
harmonic Fre.
Range (MHz)
5760–5940
5550–5730
5130–5355
RF Specifications
5GHz WIFI
Operating Range
(MHz)
4910–5056; 5170–5835
4910–5056; 5170–5835
4910–5056; 5170–5835
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