Huawei ME909u-521 Hardware Manual page 53

HUAWEI ME909u-521 LTE LGA Module
Hardware Guide

Polarization
The polarization of an antenna is the orientation of the electric field vector that rotates
with time in the direction of maximum radiation.
The linear polarization is recommended for the primary/secondary antenna of
ME909u-521 module. The RHCP (Right-Hand Circular Polarization) is recommended
for GPS antenna.
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 commonly 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 omnidirectional in the horizontal
plane, and the incident waves of base stations are often in the horizontal plane. For
this reason, the receiving performance is optimal. We must notice that GPS signal is
coming from the satellite in the outer space, it means that the incident waves are over
our head.
The following radiation patterns are recommended for the antenna of ME909u-521
module.


In addition, the secondary antenna's pattern should be complementary with the
primary antenna's pattern.
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 into
account. The appropriate antenna gain prolongs the service life of relevant batteries.
The following antenna gain is recommended for ME909u-521 module.



ECC of the antenna
ECC is short for Envelope Correlation Coefficient. It is the cross-correlation value of
the complex patterns of the master and diversity antenna. It indicates how similar the
Issue 05 (2017-12-15)
Isolation between the primary (secondary) antenna and the Wi-Fi antenna ≤ –15
dB
Primary/Secondary antenna: omnidirectional.
GPS antenna: directional, point to the space.
Gain of the primary antenna ≤ 2.5 dBi
Gain of the secondary antenna ≤ 2.5 dBi
Gain of the GPS antenna ≥ 3 dBi
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
RF Specifications
53