Small Antenna Vs. Big Antenna for the Noob

by X0n1T3 in Circuits > Wireless

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Small Antenna Vs. Big Antenna for the Noob

Tiny.jpg

I should first say that this instructable is NOT for the "PRO" or experienced user... This is mainly for those who are new or are stepping outside their comfort zone and want a quick reference but do not want a huge lecture on wireless technologies... And hopefully with a better WiFi reception, You'll be able to enjoy some sun outside the home...

Yes, there are 1000+ WiFi antenna instructables out there:

https://www.instructables.com/howto/wifi+antennas/

Yes, there are many "stock antenna" mods out there such as:

https://www.instructables.com/id/Modify-a-Stock-Wif...

And even this one which hacks the same antenna I am about to use for this instructable...

https://www.instructables.com/id/Hawking-7dBi-Wifi-...

However, I am not hacking anything, I am not reinventing the wheel here... I am just going to test the theory (question) of: "what happens if you switch a flimsy stock antenna with a more robust antenna?"

SO, if you are still reading :D ... If you have NO idea what a dBm or a dBi is you can read the following document hosted by the FCC:

http://wireless.fcc.gov/outreach/2004broadbandforu...

Alright, on to the next step...

The Stock Antenna and Basic Chipsets

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I am currently using a Lenovo ThinkCentre M600 "Tiny" with a really small 4.5" antenna and a Intel Dual-Band Wireless-AC 8260 (2x2, 3rd Gen, 2015)

However, before I even jump to the antenna I want to point out a few things everyone should know about WiFi AC:

> Everything is standard WiFi AC right?

Well, the AC standard has many optional elements and are not mandatory. So, even if you pay $400 for your AC router you might not get the "Mu-MiMo" standard built-in...(for example.)

>Mu-MiMo?

This basically has 2 options,(on the 5GHz band) 4 antennas or 8 antennas and allows multiple users to send and receive multiple streams at the same time. Under theory, if you have 4 antennas you can achieve a total of 3.39Gbit/s. If you have 8 antennas you can achieve a total of 6.77Gbit/s

> What is this Basic & Advanced AC?

The 802.11 AC WiFi standard was released in 2013 and the speeds "range" from 433 Mbps to 2.1Gbps. Some companies have 3 to 4 routers for the same WiFi AC standard. The only difference between them is the speed you get.( i.e.: Basic = 433Mbps, Medium =867Mbps, Advanced = 1.3Gbps, Pro = 2.1Gbps) This also allows manufacturers to charge a premium for basically the same technology (over and over again.)

Great example:

http://us.dlink.com/products/connect/ac5300-ultra-...

- The 2.1Gbps is a "theoretical" speed and is never achieved in the real world. ;) -

> 1x1 / 2x2 what?

When you start shopping for a new PC or router you'll now hear or read names like:

Cow Master 2000 WiFi AC 1X1

or

Pigs Fly 3000 WiFi AC 2X2

So, what exactly is that 1x1 or 2x2... You will also notice that there is a premium price between 1x1 and 2x2. Oh! , for the record there is also a 3X3 / 4x4 ...

In a nutshell, the 1x1 is telling you that it supports 1 data stream (single antenna, 433Mbps) and 2x2 supports 2 data streams (dual antenna, 867Mbps.)

> So, If you have a 2X2, 867Mbps AC chip, everything should now work at top speed, right?

Mmm... well, yes and no, data rate falls as more clients are added to the AC Access Point. So, if you have 2 devices, each gets 433Mbps. If you have 4 devices each gets 144Mbps...etc...

> What is the difference between "AC 600" and "AC1900," as some manufacturers advertise their products as such?

Well basically those are marketing terms. For example, the AC600 is the same as 150 Mbps (2.4GHz band) and 433Mbps (5GHz band.) The AC 1900 is the same as 600Mbps and 1.3Gbps respectively...

Meet the Antennas ( Antennae :p )

IMG_3379.JPG

I'm one of those freaks that jumped on the: "Big Antenna is Better" bandwagon and got the Hawking antenna back when it first came out and paid a premium for it. Nowadays, you can find it for cheap...(you can find better and bigger antennas for next to nothing.)

As I said before the stock antenna in my PC is only 4.5 inches and is rated as a 2 dBi for the 5GHz band and 3 dBi for the 2.4GHz band (As far as I know.) So, the replacement antennas should give an "amazing" bump (take it with a grain of salt) on signal power and reception...

Stock 5GHz 2 dBi > upgrade to > 5dBi

Stock 2.4GHz 3 dBi > upgrade to > 7dBi

Ironically, as outlined in this instructable:

https://www.instructables.com/id/Hawking-7dBi-Wifi-...

The Hawking antenna has a lot of signal loss due to the long cable. So, under theory I could be losing 1dBi even before it is installed (i.e.: this antenna could be a 6dBi and not a 7dBi) ... who knows...

Signal Without an Antenna...

DBM-0.PNG

Even without the external antenna there is enough internal cable (antenna) to get a pretty decent signal...

I should point out that when talking about dBm (the software I was using only shows dBm and not dBi) the closer you are to 0 dBm the better your signal. (i.e.: -5 dBm is better than -20 dBm)

Also, under theory, if your dBm reaches -90 dBm, your device (PC, tablet, phone, etc.) will start to scan for a better connection.(so, it practically means the signal is lost at this point.)

Stock Vs. Robust Antenna on the 5GHz Band...

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DBM-BIG-ant.PNG

No antenna to stock 4.5 inch antenna:

-46 dBm to -31 dBm (15 dBm gain)

Stock 4.5 inch antenna to Free 8 inch antenna:

-31 dBm to -29 dBm (2 dBm gain)

So, that was not a shocker but I was expecting a little better than just 2 dBm in improvement...(especially because the replacement antenna is practically 2X the size.)

Currently, my signal quality with the stock antenna is at 99% assuming that 100% is a theoretical number and can't be achieved in a real world environment... I do not see why I would ever need to switch antennas...

However, if your signal quality is lower than 90% then those 2 extra dBm might mean the world to your current setup.

Stock Vs. Robust Antenna on the 2.4GHz Band...

DBM-2.4GHz-WiFi-NORMAL.PNG
DBM-2.4GHz-WiFi-Hawking.PNG

Stock internal antenna to Hawking's external antenna:

-33 dBm to -28 dBm (5 dBm gain)

A 5 dBm gain, Now that's what I am talking about... The Hawking antenna does make a notable improvement over the stock antenna.

The signal quality also bumped up nicely when connected to the 2.4GHz band...

If you are one of those who divides their electronics into 2 categories such as:

TV, Roku, Media server, PS4 go on the 5GHz band

and

Laptop, tablets, Wemo, etc. go on the 2.4GHz band

Then the upgrade to a bigger antenna will improve your experience... However, having a bigger antenna does not always mean a better signal. Some antennas will change the shape of the radiation pattern. There is also a power limit (If you want more power, you need more juice applied to the antenna signal.) That said, there are times when the antenna might have the opposite (negative) effect on the WiFi signal...

So, I hope this small instructable has helped clear a few things you have been wondering about. Now you can go on and explore the plethora of WiFi projects out there starting with these:

https://www.instructables.com/howto/wifi+antennas/

- cheers!