Understanding dB Math

Рет қаралды 17,262

Күн бұрын

Download all the resources here: www.wlanpros.com/dbmath
One of the "Wireless LAN Design Rules" is, as a designer you need to understand dB math because you're going to be using it for many things. So, in this video, we're going to talk about some quick ways you can learn to do dB math, even in your head and we'll finally end up with am Excel spreadsheet you can play with so you can reinforce the knowledge.
Chapters:
00:00 - Start
00:46 About dBm (decibels compared to 1 milliwatt)
01:28 Easy dB Math in 5 minutes (Rules)
03:07 Easy dB Math in 5 minutes (Trial)
05:53 dB Math Cheat Sheet
08:02 Excel Spreadsheet (dBm to mW Conversion)

Пікірлер: 31

@pauloche9346 Ай бұрын

'You are such a great cheat'. 🤣. Anyways, thanks for the trick. Works like magic.

@KK-rg3nj 3 ай бұрын

Thanks for this video! Pretty systematic way of doing this mentally. We can also modify this to the voltage log/dB expression of YdB = 20log(x) by changing the values in the dB column to 2x ie, 20 dB => 10 and 6dB => 2. So for example: 60dB would become: 20+20+20 = 10^3 = 1000 times And 26dB would be: 20+6 = 10*2 = 20 times Appreciate your effort to simplify this!

@Kof_Believer 3 ай бұрын

I just subscribed. Thanks

@isolinear9836 Жыл бұрын

Thanks a lot Sir. This will be really useful as a template for me to teach other people. A shame nobody taught me this method decades ago. I've been doing it the "way you're supposed to" mentally (with my personal shortcuts developed over the decades, so there's no point in me using your methodical shortcuts now), but it would have been easier on me if I'd been taught this from the beginning. I remember struggling to do the math in my head when I was a kid. Ah well, at least I get to use this method in teaching others which seems a LOT easier to articulate and demonstrate.

@victornjoroge562 3 жыл бұрын

Magical! Great video..Thanks Keith for sharing this

@mahendrachavan1831 Жыл бұрын

No idea why it took so long to get this video, Sir...Thank you a Billon Tons!!!! 😀

@akshaychavan9308 3 жыл бұрын

Great video...now its far more clear

@WirelessLANProfessionals 3 жыл бұрын

Thanks again Akshay

@kasiviswanathan9505 3 жыл бұрын

Best video .. perfect .. thanks

@WirelessLANProfessionals 3 жыл бұрын

Thanks Kasi!

@joelourenco4621 3 жыл бұрын

Thank you so much!! I appreciate this.

@wongalex9457 Жыл бұрын

Thank you, I struggle for so long of this

@qzorn4440 2 жыл бұрын

very nice for an esp32 arduino wifi project... now to remember this great info 6 months from now and longer... 👍👍 thanks a lot...😉

@WirelessLANProfessionals 2 жыл бұрын

Glad it helped. Thank you for watching!

@deedoi Жыл бұрын

Thank you so much!

@MrVineetkumargupta 2 жыл бұрын

Great method to calculate dbM to mw

@WirelessLANProfessionals 2 жыл бұрын

Glad it was helpful! Thanks for watching!

@onlyonetony Жыл бұрын

YES!

@jspaceboy1117 3 жыл бұрын

How would you go from normal to db? For example 500 Watts? I think I figured it out but want to make sure (10*10*5 --> 10+10+7 = 27)

@WirelessLANProfessionals 2 жыл бұрын

Thanks for your insight! We'll just have to reverse the conversion. In this case, 500 mW would be: [(10x10x10)/2] ---> [(10+10+10)-3 = 27] Remember that there are only 3s and 2s, no 5s. 🙂

@Dylan-ni1tc Жыл бұрын

Hello, I have a question. I learned an equation which simplifies converting dB to dBm (by using this following eq, dBm = dB + 30) at college in my freshmen year. But now, fast forward almost 4 years later, I found that this method is highly debateable amongst telecom engineer. And right now, i'm in a desperate situation about this converting dBs stuff. I need to finish an eq which involves dBm and dB. My eq problem is Rx (dBm) = Tx (dBm) - Pathloss (dB), I have the data for Rx and Tx in dBm, but I need to know whats maximum distance in the PL equation (Cost231-Hata model). Is it allowed to use this methods? If not, how can I find the maximum distance? Thank you.

@theofanisc.karagiorgos9520 10 ай бұрын

what about dBm =-110 i.e? should add the "-" after the calculation? or start with 1/10*10*10*10*10*10*10*10*10*10*10?

@dinyarbuhariwalla1120 2 жыл бұрын

Hello Sir, how will you convert a decimal mw to dbm? for eg if i want to convert from 25 milli watt to dbm?

@holmiumh Жыл бұрын

Well, you can always use a calculator, but if you want to do an approximation without tool then here's one way to do it, let's say you want to convert 25 mW to dBm? 1, You know by heart that 20dBm = 100mW (if you don't know why, review definition of dBm and dB) 2, You know by heart that -6 dB = -3 -3 dB ≈ 0.5 x 0.5 = 0.25 (if you don't know why, review the approximated usage of ±3dB) 3, 25mW = 100mW x 0.25 ≈ (20 - 6) dBm = 14dBm

@MrGeronimo Жыл бұрын

Prof. -48dbm is it good or not good for 100Mbps internet fiber optique 😂 or shouldn’t be like that 🙃

@piotrstukin9274 Жыл бұрын

Why there is a 1* in the formula?

@phillipkluttz6553 3 жыл бұрын

Keith, The link to the resources returns "No results found".

@WirelessLANProfessionals 3 жыл бұрын

Phillip, my apologies - let me see what if I can get that fixed.

@WirelessLANProfessionals 3 жыл бұрын

Phillip, the resources links were there - at the bottom of the page - I reorganized the page so the resources are easily and accessible up top. Sorry for the confusion there :) Let us know I you have any other issues.

@phillipkluttz6553 3 жыл бұрын

@@WirelessLANProfessionals Thank you! The page loads now.