Antenna Design Requirements; Antenna Design Indicators - Huawei ME909u-523 Hardware Manual

HUAWEI ME909u-523 LTE LGA Module
Hardware Guide

4.5 Antenna Design Requirements

4.5.1 Antenna Design Indicators

Antenna Efficiency
Antenna efficiency is the ratio of the input power to the radiated or received power of
an antenna. The radiated power of an antenna is always lower than the input power
due to the following antenna losses: return loss, material loss, and coupling loss. The
efficiency of an antenna relates to its electrical dimensions. To be specific, the
antenna efficiency increases with the electrical dimensions. In addition, the
transmission line from the antenna port of ME909u-523 module to the antenna is also
part of the antenna. The line loss increases with the line length and the frequency. It is
recommended that the line loss is as low as possible.
The following antenna efficiency (free space) is recommended for ME909u-523
module to ensure high radio performance of the module:



In addition, the efficiency should be tested with the transmission line.
S11 (VSWR) and S21
S11 indicates the degree to which the input impedance of an antenna matches the
reference impedance (50 Ω). S11 shows the resonance feature and impedance
bandwidth of an antenna. Voltage standing wave ratio (VSWR) is another expression
of S11. S11 relates to the antenna efficiency. S11 can be measured with a vector
analyzer.
The following S11 values are recommended for the antenna of ME909u-523 module:



In addition, S11 is less important than the efficiency, and S11 has not strong
correlation to wireless performance.
S21 indicates the isolation between two antennas.
Issue 01 (2014-05-24)
Maximum Power Reduction (MPR) of LTE is according to 3GPP TS 36.521-1 as below. And
Additional Maximum Power Reduction (A-MPR) of LTE is according to 3GPP TS 36.521-1 6.2.4
section.
Efficiency of the primary antenna: ≥ 40% (below 960 MHz); ≥ 50% (over 1420
MHz)
Efficiency of the secondary antenna: ≥ half of the efficiency of the primary
antenna in receiving band;
Efficiency of the GPS antenna: ≥ 50%; Upper Hemisphere efficiency≥ 50%
S11 of the primary antenna ≤ –6 dB
S11 of the secondary antenna ≤ –6 dB
S11 of the GPS antenna ≤ –10 dB
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RF Specifications
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