Eirp là gì

E.I.R.P.Bạn đang xem: Eirp là gì (Effective Isotropic Radiated Power) - is an equivalent effective isotropic radiated nguồn defined as a nguồn that would have to be radiated by a hypothetical isotropic antenna lớn achieve identical signal level in the direction of maximum radiation of a specific antenna.”

In accordance lớn Polish & EU regulations, the maximum power nguồn that can be used to lớn transmit in the specific WLAN frequency range (exceeding the power nguồn means that you are breaking the law):

2400,0 – 2483,5 MHz (2.4 GHz band) - power up lớn 100 mW E.I.R.P. (20 dBm),5150 – 5350 MHz (5 GHz band) - power up lớn 200 mW E.I.R.P. (23 dBm) - for indoor use only,5725 – 5875 MHz (5 GHz band) - power nguồn up lớn 1000 mW E.I.R.P. (30 dBm).Bạn đang xem: Eirp là gì

Consider the following to lớn prevent E.I.R.P. Thresholds from being exceeded:

For a system including a transmitter (e.g. A wireless router), cable and antenna, E.I.R.P. Is calculated from the following formula:

E.I.R.P. = p. – l x Tk + Gi

P – transmitter nguồn in dBml – cable length in metresTk – attenuation for 1 metre of cable at operating frequency of the transmitterGi - power nguồn gain of the isotropic antenna in dB

To simplify:

E.I.R.P. = transmitter power nguồn (dBm) + antenna gain (dBi) – cable attenuation (dB) – connector attenuation (dB)

To simplify, attenuation of a single connector is = 0.5 dB

Example. WLAN operating at 2,4 GHz band:

16 dBm access point, 8 dBi omnidirectional antenna,8 metre cable TRI-LAN-240 (attenuation for 2.4 GHz is 0.4 dB / metre), i.e. 8 x 0.4 dB = 3.2 dB,two connectors – attenuation + 2 x 0.5 dB = 1 dB.

Calculation:

Example: for a 13 dBi gain antenna:

E.I.R.P. = 16 dBm + 13 dBi – 3,2 dB – 1 dB = 24,8 dBm (i.e. Exceeded by 4,8 dBm!)

Remember, not all access points reduce the output đầu ra power.

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Thus, it is better to use a high gain antenna and a low power nguồn transmitter than a low gain antenna and a high power nguồn transmitter. The devices operate not only in transmission, but also reception mode, và thus the sensitivity of the receiver is also important.