Siemens 6GT2810-2BB80-0AX1, Системное руководство

Страница: 306 / 506

Antennas
6.5 SIMATIC RF642A
SIMATIC RF600
306
System Manual, 06/2019, J31069-D0171-U001-A22-7618
6 6.5.6.3 Interpretation of directional radiation patterns
The following overview table will help you with the interpretation of directional radiation
patterns.
The table shows which dBi values correspond to which read/write ranges (in %): You can
read the radiated power depending on the reference angle from the directional radiation
patterns, and thus obtain information on the read/write range with this reference angle with
regard to a transponder.
The dBr values correspond to the difference between the maximum dBi value and a second
dBi value.
Deviation from maximum antenna gain [dBr] Read/write range [%]
0 100
-3 70
-6 50
-9 35
-12 25
-15 18
-18 13
Example
As can be seen in Directional radiation pattern in the ETSI frequency band (Page 303), the
maximum antenna gain in the horizontal plane is 6 dBi. In this plane and with the parallel
polarization axis at +70° or 300°, the antenna gain dropped to about 0 dBi. Therefore the dBr
value is 6. The antenna range is only 70° of the maximum range at + 50° or +300° from the Z
axis within the horizontal plane (see values shown in red in the directional radiation pattern:
Characteristic of the vertical plane of the antenna (Page 302) and the associated
representation of the reference system (Page 302)).