Siemens 6GT2812-2EA00, Руководство по эксплуатации

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Antenna patterns
5.4 Interpretation of directional radiation patterns
SIMATIC RF622A
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Operating Instructions, 11/2020, C79000-G8976-C601-01
5.4 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 you can see in the pattern in the section "Antenna patterns in the ETSI frequency band
(Page 18)", the maximum antenna gain is -5 dBi. In the vertical plane, the antenna gain has
dropped to approx. -10 dBi at +40° and 320°. This means that the dBr value is -5. The antenna
range is only 50% of the maximum range at ± 40° from the Z axis within the vertical plane
(see line shown in blue in the directional radiation pattern: Characteristic of the vertical plane
of the antenna and the associated representation of the reference system).