Siemens SIMATIC RF600 Series System Manual page 54

RF600 system planning
4.3 Antenna configurations
the values and their effect on the transmit/radiated power are calculated directly. With third-
party products, you can enter the relevant values manually.
Based on the entered products/values, the WBM calculates the permitted radiated power
and makes sure that this is not exceeded.
4.3.9.4 Types of antenna
Basically all types of directional antennas can be considered as third-party antennas for
integration into the SIMATIC RF600 system. Directional antennas have a preferred direction
in which more energy is radiated than in other directions.
RF600 antennas on the other hand, are optimized for operation with RF600 readers and
have all the required approvals.
4.3.9.5 Antenna cables
Selection criteria
You must observe the criteria listed below when selecting the appropriate antenna cable.
Characteristic impedance
Definition
If the input impedance of a device does not agree with the cable impedance, reflections
occur which reduce the power transmission and can result in the appearance of resonance
and thus to a non-linear frequency response.
Specifications
● You must only use coaxial antenna cables when connecting a third-party antenna.
● This antenna cable must have a nominal characteristic impedance of Z = 50 Ohm.
Antenna cable loss
In order to be able to transmit the available UHF power from the RF600 reader to the
antenna or antennas, the antenna cable loss should not exceed a value of approx. 5 dB.
Dependency of the cable loss
The cable loss depends on two important factors:
● External characteristics of cable. These includes the cable length, diameter and design.
● As a result of the physical principle, the cable loss is also frequency-dependent. In other
words, the cable loss increases the higher the transmitter frequency is. Therefore the
cable loss must be specified in the frequency band from 860 to 960 MHz.
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System Manual, 10/2016, J31069-D0171-U001-A19-7618
SIMATIC RF600