Banana Pi BPI-R4 Wifi 7 BE14 - Pigtails and Antennas

[SpectreDev]

So best to go for the other one I guess

[Thanks]

As far as I know, and I may be wrong, both tri-band dipole antennas from Taoglas are good, but the “gain” of the older antenna is 3 dBi on most bands and the “gain” of the newer antenna is 5 dBi on most bands; the one with higher gain ratings will give you a little extra range, but you pay more for it.

Information about antenna “gain”:

• How Antenna Gain affects Range in FPV
• dBi, dB, dBm dB(mW): Defined, Explained and Differentiated
• Antenna Gain Explanation
• To Gain or Not to Gain…That is the Antenna Question
• 8dbi vs 5.8dbi vs 3dbi - Which cables & connectors to choose to reduce signal loss?

@VA1DER

First, remember that about 99% of the antennas that say they are 5dBi gain are really just dipoles that have an actual gain of 2.14dBi. So don’t be too trusting of those dB gain numbers you see.

Next remember that “gain” in an antenna isn’t actual gain in the sense you get from an amplifier. It’s shaping/sensitivity in a particular direction at the expense of loss in another. The “i” means isotropic, which is a theoretical antenna that is a perfectly omnidirectional radiator. 5dBi means in one direction or plane the antenna radiates more strongly by 5dB, and in other areas it radiates 5dB weaker. Here is the radiation pattern of a standard dipole, looking at it from the side. Don’t look at the ring numbers, the outer ring is actually set to 2.14dBi, which is the actual gain of a dipole.

You will naturally get more than the normal 2.14dBi dipole “gain” just because you have more than one dipole. As I mentioned, two dipoles tend to focus the signal not just in the squished plane of a single dipole, but also linearly (like the CB radios example).

My advice is to use normal dipoles and if there is extra shaping you want to do, arrange the antennae in such a way as their mutual emission pattern shapes the signal.

@VA1DER

For gain, as mentioned, MOST of the gain numbers in ads on AliExpress or even Amazon are fairy tales. A dipole gives 2.14dBi gain. A thee element colinear might give 5 or 6dBi gain but will be 40cm long. To get the 8-12dBi gain claimed by some, you’d need a colinear antenna that’s a good 1m long. These exist, but aren’t really practical.

The gain of those antenna shapes the signal to be more and more like a frisbee (a dipole is like a donut), flattening it out. Maybe good for single-floor, but very strongly polarized, and harder to make efficient and broadband.

I tend to stick with normal dipoles

[SpectreDev]

Cool thanks, the stock ones are horrible I can’t even get a signal upstairs in my house and if I do it’s running at 5mbps lol, compared to my router provided by isp that can do 300mbos in my weakest room

[totkeks]

I’m using these https://www.amazon.de/dp/B09V4YXMZN as I needed longer pigtails. They seem to work so far, but haven’t done any speedtests or analysis on the signal quality yet.

[Betonmischer]

I’d like to share new data about the Antsym 5 GHz antennas that I’ve purchased as a replacement for the stock BPI ones. Now that I’ve done signal measurement (at 2.5 meters in direct line-of-sight) it looks like they’re not any better after all. I guess that does it for cheap antennas for me. I’ll try to get my hands on those rather expensive tri-band antennas from Taoglas and report back on how they perform.

band	brand		router signal	NIC signal/noise	
5ghz	sinovoip		-15			-38/-77
5ghz	antsym			-14			-39/-74

6ghz	sinovoip		-25			-39/-76
6ghz	antsym			-27			-43/-75

[Thanks]

I think this is the correct way to place the WiFi and Cellular antennas on the BPI-R4 when you have a WiFi 7 module (BE14) and a 5G module (RM520N-GL) installed. It is recommended that the cable has the same length for all antennas on each radio, maybe 20 cm cables (IPEX-1) for all WiFi antennas (mentioned above) and 10 cm cables (IPEX-4) for the Cellular antennas:

Antenna Placement #1
--------------------
2/5g         6g
Leave this space between WiFi antennas or use it for cellular antennas
6g           5g
2/5g         6g

.

Antenna Placement #2
--------------------
5g           6g
Leave this space between WiFi antennas or use it for cellular antennas
6g           2/5g
2/5g         6g

.

Antenna Placement #3
--------------------
5g           6g
Leave this space between WiFi antennas or use it for cellular antennas
6g           6g
2/5g         2/5g

.

Antenna Placement #4
--------------------
       5g
6g           6g
Leave this space between WiFi antennas
Leave this space between WiFi antennas
2/5g        2/5g
       6g

Information about cable and antenna placement:

@VA1DER

Pigtails: I tend to use RG178. It is about the thickest cable that is feasible to use with U.FL connectors. I find it’s got the best loss characteristics while still being flexible enough to use. I recommend for each radio to use four cables the same length - this helps with beamforming. I keep a lot of 20cm cables since I find they are a good general purpose size for these types of cases.

@VA1DER

I asked myself also about antenna configuration. I mixed them 2 by 2. So on each side I have 2 antennas for 2.4 Ghz and 2 for 5GHz

This is a very reasonable orientation, and is great for a centrally located router.

Antenna configuration is actually a pretty complex topic. The answer depends very much on your home layout, how many walls and floors you need to penetrate, and on the very complex way in which multiple antennae shape a signal

In general a dipole radiates strongest in a plane 90 degrees from the direction it points (along the broadside of the antenna). Multiple dipoles tend to shape that signal more strongly in the direction 90 degrees from the direction the antennae are lined up (out from the “flat” of the two antennae). This is why truckers often had two CB antennae, one on either side of the cab on its mirrors, as they shaped the signal more strongly ahead and behind the truck. If your signal cables are different lengths, though, this will introduce e a phase change in the antennae that will induce deflection, and is the way phased arrays work. At 5GHz, which is a wavelength of about 5cm, it doesn’t take much difference in cable length to induce a significant phase shift and this will make your signal pattern very resistant to prediction.

My primary router, for ease of installation, is placed at the far end of my house on the second floor. So I placed all four 5GHz antennae on one side and shaped their flats to be more strongly radiating toward the house. I was less concerned about 2.4GHz since it has much better penetration, and found that I got sufficient coverage even with them being on the other side of the router. But I am sacrificing some 2.4GHz signal to improve my 5GHz throughout my house.

If your router is fairly central, then 2 & 2 is a great idea. Just don’t forget your upstairs and basement (if you have any).

@VA1DER

P.S i only have to cover one floor so no need for a certain angle. Jus keep em all straight Up, correct?

I’d likely rabbit-ear them a little, just to help the signal spread around objects, and to help with polarization.

A dipole puts out a signal polarized in the direction it points. Like polarized light. The antennae in devices tend not to be dipoles - they try and make them fairly omnidirectional, but that’s not possible in all instances (and given the flatness of phones and tablets). So if you have 100% vertical polarization in your router, but your device has an antenna that is more sensitive to a signal with horizontal polarization, then even given good signal strength you’ll lose signal. So rabbit ear them a little, or maybe lay one down, just to mix up the polarization in your footprint.

a 3d case model which has 4 left and 4 right, should we make 2g4 on one side and 5g on the other to have less interference or is mixing better as they operate on different base-band and so no interference happens?

For a centrally located router on a single-floor dwelling, with a 4+4 antenna placement on the case, I would recommend dipole antennae with the 5GHz placed in the corners and 2.4GHz placed in the middle on either side:

5g    5g
2g4  2g4
2g4  2g4
5g    5g

Even when they are not broadcasting together or on the same frequency, the physical placement of the other antennae will still shape the signal. In a 4+4 arrangement, you can expect each antenna to produce primary lobes that look something like this:

The first diagram shows the pattern coming out from the left and right antennae, and for clutter I omitted the signal coming the other way… The second diagram is showing the approximate signal pattern in both directions from the left antennae. These are both significant oversimplifications, and are based on all antenna being straight up. You can, for example, improve the right-hand radiation pattern of the left antennae by laying the top or bottom one down. So if you had 5g on one side and 2.4 on the other, I would likely lay the top antenna on the left side down and the bottom antenna on the right side down.

But for a centrally located router on a single floor dwelling, 5G in the corners and 2.4G in the middle will likely give the best general coverage.

@dangowrt

Instead of connecting all 2.4 GHz antennas on one side and all 5 GHz antennas on the other side you will get better results if you interleave them and thereby maximizing the distance between antennas which are used for the same band. 2~3 cm between two antennas of the same band will not allow for good results with MiMo, the more distance between them, the better…

[SpectreDev]

Btw if anyone reads this later, the 2nd one is available cheaper at digikey

[rmandrad]

this is a great explanation on all this works & thank you however 6Ghz/EHT is not mentioned apart from the pics … any other points to make for 6GHz ?

[kusmi (Michael Kussmaul)]

And how would you recommend to orient the antennas? Is there also a recommendation? (Eg one horizontal, one vertical, …)

[SpectreDev]

I purchased the antennas and will post here how they go

[Thanks]

@rmandrad

however 6Ghz/EHT is not mentioned apart from the pics … any other points to make for 6GHz ?

1. MiMo works equally on all radios/bands, which means that the above information about cable and antenna placement on the 2.4 GHz and 5 GHz radios also applies to the 6 GHz radio.

• As explained here:

  @psyched_engi_girl

  Taking advantage of antenna diversity means placing your antennas in different locations and at different angles which causes each antenna to bounce their waves in different ways around your home. This is why routers often place their antennas as far apart as possible. If you placed two antennas on opposite ends of your desk with a few degrees of angle between them, it will allow your NIC to dynamically switch between paths that give it the best signal to noise ratio to the router and vice versa.

2. The 6 GHz band has worse penetration through walls, objects, floors and ceilings than the 2.4 GHz and 5 GHz bands.

• As explained here:

  @Tom's Guide

  “Higher frequencies mean shorter range, and the 6-GHz frequency is so high that its range is limited to same-room or next-room connections.”

3. Behfor recommends using the bands in this way and makes a ping comparison between them:

• 6 GHz: Gaming PC, Virtual reality (Meta Quest) and Mesh backhaul.
• 5 GHz: Laptops, tablets, smartphones and Mesh backhaul (better choice for backhaul).
• 2.4 GHz: IoT devices.

ASUS ROG Rapture GT-AXE11000 - One Year Later !

@kusmi

And how would you recommend to orient the antennas? Is there also a recommendation? (Eg one horizontal, one vertical, …)

Watch these videos, they show you where to place the wireless router in your home and the best antenna positions for the wireless router:

1. Where to place the wireless router in your home.

2. Optimal Positions for Your Router’s Antennas in a Single Story House.

3. Best Antenna Positions for Wireless Router in a 2-Story House.

[SpectreDev]

New Taoglas antenna with new rg178 cables

Old antenna with old cables

Both in direct line of sight 6ghz

Signal strength is also much better than previously, these antennas are really good, quite happy with the purchase

[Betonmischer]

Now that’s pretty decent improvement. Would you mind posting the signal strength figures?

[SpectreDev]

Top of the staircase in my house

I’ll get 6Ghz up in a bit

Edit: 6ghz

[Betonmischer]

Very dramatic difference, thank you.

[SpectreDev]

Only issue is while the signal is stronger than my isp router i still cant get 5ghz in my weakest room while the ISP one can

[totkeks]

Which tools (Windows, Linux or Android app?) are you using to measure the signal quality?

I’m planning to put the antennas on the outside of the door of the cabinet (drilling some holes, but don’t tell anyone). Reading the above it sounds like the distribution of the antennas is important.

I was thinking about just placing all six of them in a line. • • • • • • Should I alternate the 2.4/5g and 6g in this case?

Another idea could be two lines. One of them for 2.4/5g and the other for 6g.

• • •
• • •

Or some funny circular options, though not sure if that makes sense.

 •  •
•    •
 •  •

[SpectreDev]

Its wifiman from ubiquity

[rmandrad]

this is a great topic and must say one of the advice to flattening the antennas helped a lot with the reach of the phy2 radio … is there a feature to star this topic ?

[SpectreDev]

yeah flattening helped me out too, but still get blackspots on my xperia weirdly