Huawei ME909u-521 - Co-Exsitence with 5 Ghz WIFI Design Guide; Purpose; Co-Exsitence Design Main Point

HUAWEI ME909u-521 LTE LGA Module
Hardware Guide
RF Specifications
Issue 05 (2017-12-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
55
Antenna Requirements
Bandwidth of
secondary antenna
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
Bandwidth of GPS
antenna
35 MHz in GNSS
Gain
≤ 2.5 dBi (≥ 3 dBi for GPS antenna)
Impedance
50 Ω
VSWR absolute max
≤ 3:1(≤ 2:1 for GPS antenna)
VSWR recommended
≤ 2:1(≤ 1.5:1 for GPS antenna)
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
nd
or 3
rd
harmonic with the frequency about 5
GHz, so that will deteriorate 5 GHz WIFI receiver performance. That is why
Co-exsitence design needed.
Operating Band
Tx
Frequency
range (MHz)
2nd order
harmonic
Fre. Range
(MHz)
3nd order
harmonic Fre.
Range (MHz)
5GHz WIFI
Operating Range
(MHz)
Band 1 (UMTS, LTE)
1920–1980
3840–3960
5760–5940
4910–5056; 5170–5835
Band 2 (UMTS, LTE), GSM1900
1850–1910
3700–3820
5550–5730
4910–5056; 5170–5835
Band 3 (LTE), GSM1800
1710–1785
3420–3570
5130–5355
4910–5056; 5170–5835
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.