Interference - Huawei MU609 Mini Hardware Manual

HUAWEI MU609 Mini PCIe Module
Hardware Guide
Envelope Correlation Coefficient
The envelope correlation coefficient indicates the correlation between different
antennas in a multi-antenna system (primary 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 primary antenna and the diversity antenna
indicates a high diversity gain. The envelope correlation coefficient depends on the
following factors:
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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 primary antenna and the diversity antenna is smaller than 0.5.
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 MU609 module. Gain of the master
antenna ≤ 2.5 dBi

4.5.2 Interference

Besides the antenna performance, the interference on the user board also affects the
radio performance (especially the TIS) of the module. To guarantee high performance
of the module, the interference sources on the user board must be properly controlled.
On the user board, there are various interference sources, such as the LCD, CPU,
audio circuits, and power supply. All the interference sources emit interference signals
that affect the normal operation of the module. For example, the module sensitivity
can be decreased due to interference signals. Therefore, during the design, you need
to consider how to reduce the effects of interference sources on the module. You can
Issue V0.1 (2013-05-16)
Distance between antennas
Antenna type
Antenna direction
 The antenna consists of the antenna body and the relevant RF transmission cable. Take the
RF transmission cable into account when measuring any of the preceding antenna
indicators.
 Huawei cooperates with various famous antenna suppliers who are able to make
suggestions on antenna design, for example, Amphenol, Skycross, etc.
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RF Specifications
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