RFD900ux Data Sheet
www.rfdesign.com.au
6
Last update 12/09/2019
4
Output power levels
Many countries have different legal power levels. Be sure to operate within the legal power limits of
the country that you are operating in. The RFD900ux modem can support the power levels between
0dBm and 30dBm in 1dBm steps. Formula 2-1 can be used to convert the power in dBm into milliwatts.
𝑃
𝑚𝑊
= 10
(𝑃
𝑑𝐵𝑚
10
⁄
)
Formula 2-1
To calculate Effective Isotropic Radiated Power (EIRP) you can use the formula 2-2 below:
𝐸𝐼𝑅𝑃(𝑑𝐵𝑚) = 𝑇𝑟𝑎𝑛𝑠𝑚𝑖𝑡𝑝𝑜𝑤𝑒𝑟(𝑑𝐵𝑚)– 𝐶𝑎𝑏𝑙𝑒𝑙𝑜𝑠𝑠(𝑑𝐵) + 𝐴𝑛𝑡𝑒𝑛𝑛𝑎𝐺𝑎𝑖𝑛(𝑑𝐵𝑖)
Formula 2-2
The FCC limit for EIRP is 4 Watts, or 36dBm for frequency hopping radios in the ISM 900 MHz band.
The Australian EIRP limit is 30dBm as defined by ACMA.
