![Huawei ME909u-521 Hardware Manual Download Page 55](http://html.mh-extra.com/html/huawei/me909u-521/me909u-521_hardware-manual_167882055.webp)
HUAWEI ME909u-521 LTE LGA Module
Hardware Guide
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.