Reg. Transmit & Receive power - RF Cafe Forums

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gopi80in

Post subject: Reg. Transmit & Receive power

Posted: Fri Dec 22, 2006 7:27 am

Lieutenant

Joined: Fri Dec 22, 2006 6:44 am
Posts: 1
Location: INDIA

Can any one tell me the reson for changing the BTS transmit power in +ve value( dBm or Wtts) while the Mobile receiving power is -ve value.

look forward for your reply

sm7ovk

Post subject:

Posted: Thu Jan 11, 2007 1:19 pm

Captain

Joined: Thu Jan 11, 2007 12:59 pm
Posts: 16

Not sure if I understand you right, but I assume that you mean that output power is mentioned for an example as +20dBm, ie 100mW. A reciever will only recieve a fraction of this and according to the logarithmics it'll be for an example -60dBm, ie one millionth of a mW.

Some more information at www.producon.com/sm7ovk/dbformula.html

Regards
Jens

nubbage

Post subject:

Posted: Fri Jan 12, 2007 4:35 am

General

Joined: Fri Feb 17, 2006 12:07 pm
Posts: 268
Location: London UK

If the power at the input to a Black Box 2 port device is +N dBm and the attenuation through the Black Box is greater than N dB, then the output expressed as dBm will be a negative value, because you have used up all the +N decibels and the "Bank Account" goes into negative territory.

Your question, as Jens implies, was rather cryptic. Some more details would help us explain better.

Posted 11/12/2012

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