RF Math Welcome to my RF MATH quiz. I made this page to collect questions for helping me get better at RF Math for my CWNA study. I made a few up as well. If you want to learn how to do the calculations check out the WiFi Ninja's Blog post on the subject. https://wifininjas.net/2019/12/19/wn-blog-024-rf-math/ A Wireless Transmitter that emits a 50 mW signal is connected with a cable with 3dB loss to an antenna with 9dBi gain. What is the EIRP on the Antenna?10 dBm13 dBm26 dBm23dBmAn outdoor access point with a power output of 40mW is fitted with a 13dBi gain Antenna. The cables are rated at 1dB of loss. It is using Channel 136 (5680MHz). What is the maximum power the Access point can be set to12dBm17dBm9dBm18dBmAn WLAN transmitter has failed. In a previous survey the EIRP was recorded as 400mW. The gain of the antenna is 7dBi and the cables have 3dB of loss. What was the power output of the transmitter?22 dBm1 W250mW17dBmA wireless bridge is configured to transmit at 100mW. The cable loss is 3dB and it is connected to a 16dBi antenna. What is the EIRP?30 dBm2000 mW8 W36 dBmA 400mW WLAN transmitter is connected using a 9dB loss cable to a 19dBi gain antenna. What is the EIRP?4 W33 dBm3000 mW35dBmA Wireless Transmitter that emits a 20 mW signal is connected with a cable with 6dB loss to an antenna with 19dBi gain. What is the EIRP on the Antenna?12dBm9dBm26dBm17dBmA Wireless Transmitter that emits a 80 mW signal is connected with a cable with 2dB loss to an antenna with 9dBi gain. What is the EIRP on the Antenna?11262317An access point needs a 5dBi antenna but you only have antenna's with dBd gain. Which antenna would be correct.7.14dBd5dBd8.41dBd2.86dBdPlease fill in the comment box below. Time is Up!

Martin Ericson March 15, 2021 at 4:00 pm Wrong answer on first question. *************ANSWER CORRECTED************ Reply

admin March 15, 2021 at 7:12 pm Thanks Martin, I realised this today when i was showing my colleague the quiz. Thanks very much for your input. If you can think of any questions for me to add please let me know. Anthony@wifiangel.co.uk. Reply

Ranganath Surpur March 19, 2021 at 12:07 pm If you give some information for the Calculation of EIRP and db calculation. Its really helpful to understand power levels Reply

admin March 21, 2021 at 3:45 pm I learnt the calculations from the CWNA book. This gives a good explanation of how to calculate EIRP. Also check the wifi ninja’s blog post on RF math. https://wifininjas.net/2019/12/19/wn-blog-024-rf-math/ Reply

Martin EricsonWrong answer on first question. *************ANSWER CORRECTED************

adminThanks Martin, I realised this today when i was showing my colleague the quiz. Thanks very much for your input. If you can think of any questions for me to add please let me know. Anthony@wifiangel.co.uk.

Ranganath SurpurIf you give some information for the Calculation of EIRP and db calculation. Its really helpful to understand power levels

adminI learnt the calculations from the CWNA book. This gives a good explanation of how to calculate EIRP. Also check the wifi ninja’s blog post on RF math. https://wifininjas.net/2019/12/19/wn-blog-024-rf-math/