Wireless Access

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Access network design for branch, remote, outdoor, and campus locations with HPE Aruba Networking access points and mobility controllers.
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rf math

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  • 1.  rf math

    Posted May 08, 2016 10:39 AM
      |   view attached

    Hi,

    How is that possible 

     

    25mW =eirp(17dBm)

     

     

    Thanks 



  • 2.  RE: rf math

    EMPLOYEE
    Posted May 08, 2016 11:01 AM

    Please show us the whole screenshot so you know what you are talking about.



  • 3.  RE: rf math

    Posted May 08, 2016 12:55 PM
      |   view attached

    Hi

    Sorry for that , i forget to post the gain part

    Thank you 

     

     



  • 4.  RE: rf math
    Best Answer

    EMPLOYEE
    Posted May 08, 2016 02:39 PM

    EIRP = Transmit power - Losses + Gains

    https://en.wikipedia.org/wiki/Equivalent_isotropically_radiated_power

     

    From your screenshot: 14mW Transmit power, 0 dB loss, 5 dB antenna gain.

     

    1 mW = 0 dBm by definition

    2 mW = 3 dBm

    4 mW = 6 dBm

    8 mW = 9 dBm

    16 mW = 12 dBm

     

    And 12 dBm (which is the 16 mW transmit power) - 0 dB (cable loss) + 5 dB (antenna gain) = 17 dBm EIRP.

     

    So the EIRP depends on the antenna gain, which makes it possible in your first screenshot that the same transmit power results into different EIRP values.