BlueBox IDTRONIC CX Industrial UHF, Руководство пользователя, Страница: 114 / 126

BLUEBOX CX Industrial UHF Page 114 of 126
Where:
P
C,max
Maximum RF output power in dBm
P
ERP,max
Maximum ERP power of the antenna in dBm
G
IC
Circular antenna gain in dBic
C
L
Cable loss in dB
A.2. Operation in North America
The FCC specifies frequency hopping across the North American spectrum
allocated to UHF RFID (902
−
928 MHz, with hopping occurring between
902.75
−
927.25 MHz in 500 KHz steps). This specification states that no listen-
before-talk is performed, the maximum continuous transmit time on a channel
is 0.4 seconds.
RF Channel Frequency [MHz]
1 902.75
2 903.25
3 903.75
… …
49 926.75
50 927.25
Other RF channels and single channel selection are present only for
test purposes and should not be used in normal operation!
FCC regulations describe the radiating power limits in relation to isotropic
antenna and EIRP (Efficient Isotropic Radiating Power) is used as a measure.
The maximum RF output power is defined by the antenna gain, the half power
beam width and the cable attenuation on the reader - antenna connection. A
power of P
EIRP,max
= 36dBm EIRP subject to a maximum conducted power of
allowance of 30dBm at the antenna connector is allowed. The maximum
BLUEBOX RF output power is defined as: