HUAWEI MU509-65 HSDPA LGA Module
Hardware Guide
RF Specifications
Issue 01 (2016-04-08)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
46
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 the 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 to ensure high radio
performance of the module: Efficiency of the master antenna:
≥ 40% (below 960 MHz);
≥ 50% (over 1420 MHz). In addition, the efficiency should be tested with the
transmission line.
S11 (VSWR)
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 MU509-65: S11 of the
primary antenna ≤ –6 dB.
In addition, S11 is less important than the efficiency, and S11 has weak correlation to
wireless performance.
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 antenna of the module.
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.
The following radiation patterns are recommended for the antenna of the module:
Primary antenna: omnidirectional.
