SNR between two wireless antenna equation
时间:04-04
整理:3721RD
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Dear all,
I'm working with CRN wireless antenna
kindly I need help in the SNR equation
suppose I have two antenna :
1- transmitting power =24 DBm
2- cable losses =1 DB at each side (Transmitter and reciever )
3- TX antenna gain 24 dbi
4- RX antenna gain =24 DBi
5- Distance between antennas =20 miles
6- FSPL=130 DB at 2.4 GHz (I calculated it )
7-assume RX sensitivity =-83 dbm
so the receiving power will be 23 dbm
but I need an equation to calculate the max distance that I can get with minimum SNR =-15 DB
?
kindly I went o Friis formula , but I cannot calculate the SNR ?
can I get it from the free FSPL ?
Sorry
receiving power will be 23 db
I'm working with CRN wireless antenna
kindly I need help in the SNR equation
suppose I have two antenna :
1- transmitting power =24 DBm
2- cable losses =1 DB at each side (Transmitter and reciever )
3- TX antenna gain 24 dbi
4- RX antenna gain =24 DBi
5- Distance between antennas =20 miles
6- FSPL=130 DB at 2.4 GHz (I calculated it )
7-assume RX sensitivity =-83 dbm
so the receiving power will be 23 dbm
but I need an equation to calculate the max distance that I can get with minimum SNR =-15 DB
?
kindly I went o Friis formula , but I cannot calculate the SNR ?
can I get it from the free FSPL ?
Sorry
receiving power will be 23 db
You have SPL right, so you should be able to calculate the received power correctly. It's not 23 dBm (and neither 23dB). SNR is the ratio of received power and receiver sensitivity.
Dear ,
you are right
the received power =-90 DB =60 DBm and can be calculated from FRIIS Formula
now the SOM = Received power - RX sensitivity = -60 DBm - (-DBm ) =23 DB ;
now the noise can be calculated as -174+Nf+10log(bandwidth) = -95 DB with NF=11 and bandwidth =6MHz
now further more :
the SNR =received power/noise = -90DB - (-95DB) =5DB ==> is this right ? or the receiver sensitivity must be included?
I get a received power of -60 dBm.
Sorry .
Typping error
-60 dBm