Table of Contents
Advertisement
3.4 The antenna cable
Use 50Ω impedance low-loss cable and high-quality 50Ω impedance connectors (frequency range up to
3GHz) to avoid RF losses. Ensure that the antenna cable is as short as possible. The Voltage Standing-
Wave Ratio (VSWR) may depend on the effectiveness of the antenna, cable and connectors. In addition, if
you use an adaptor between the antenna cable and the antenna connector, it is crucial that the antenna
cable is a high-quality, low-loss cable. Minimize the use of extension cables, connectors and adapters.
Each additional cable, connector or adapter causes a loss of signal power.
3.5 Possible communications disturbances
Possible communication disturbances include the following:
• Noise can be caused by electronic devices and radio transmitters
• Path-loss occurs as the strength of the received signal steadily decreases in proportion to the
distance from the transmitter
• Shadowing is a form of environmental attenuation of radio signals caused by hills, buildings,
trees or even vehicles. This can be a particular problem inside buildings, especially if the walls
are thick and reinforced
• Multi-path fading is a sudden decrease or increase in the signal strength. This is the
result of interference which is caused when direct and reflected signals reach the antenna
simultaneously. Surfaces such as buildings, streets, vehicles, etc., can reflect signals
• Hand-over occurs as you move from one cell to another in the GSM network. Your mobile
application call is transferred from one cell to the next. Hand-over can briefly interfere with
communication and may cause a delay, or at worst, disruption
MTX-Java-IoT | 2018/2
MTX © by MATRIX ELECTRONICA S.L.U.
SUPPORT: iotsupport@mtxm2m.com | SALES: info@mtxm2m.com |
mtxm2m.com
98
Advertisement
Table of Contents
