Forum

Hey Everyone,

I'm having a time with one of the example on page 307 in the 3rd addition of the study guide. I'm not understanding the Max power from the IR (UNII-1)at 40mW=16dBm. Here is what I did (which I know is wrong):

40mW *10dB *4dB ( 4=10-6(10-3-3) pg. 55)

I looked back to chapter 3 but I'm not find the results and getting frustrated. Can someone break it down for me.

I understand how they got the antenna gain and max EIRP.

Also could you breakdown 800mW = 29 dBm

Thanks everyone,

Psiclonius

1mW * 10 = 10mW
10mW * 2 = 20mW
20mW * 2 = 40mW

By the rules of 10's and 3's

10dBm + 3dBm + 3dBm =16dBm

Does this help?

As for the second one you asked about I will say as my old professor used to say: The math is trivial and the exercise is best left to the student :)

Of course, I think he just didn't want to do the math.

I forgot to mention that there are some errors in chapter 3. The corrections can be found in the Errata on the CWNP site. Is it possible the errors are confusing you?

Yes that helps. Now I see my mistake. I was coming up with 14dBm (adding the 2 instead of 3). Thanks a bunch, I should be ok.