1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Near field path loss with attenuation

  1. Sep 27, 2012 #1
    1. The problem statement, all variables and given/known data

    I have a 2 wireless cards with a power output of 0dBm, two 5dBi gain antennas, and a 30dB attenuator connected to each antenna. I need to figure out what the path loss will be in this scenario, so I can therefore determine the maximum distance possible between the antennas before they can no longer receive each other's signal.

    2. Relevant equations

    I know path loss in dB:

    L = 20 log_10(4 * π *d / λ)

    this one I can use to find the max distance once I know L, but I don't know how to find the path loss due to the attenuation in the first place.

    3. The attempt at a solution

    I know attenuation is:

    = 10 * log_10(power out/ power in)


    30 dB = 10 * log(power out/ odBm)

    How can I find power out from here?

    And how could I use that in the path loss equation?

    Thank you for the help.
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted