Has anyone tried the “Symmetrical Antennas” from RF elements?
http://simper.rfelements.com/assets/Uploads/Symmetrical-Sectors-Datasheet.pdf
I will be deploying sector antennas very soon for PtMP connections (back haul links for CPEs). I have zero experience with this type of setup and I must say, this stuff from RF elements looks to be better; but then again I’m very green.
Is this really better than the traditional sector antennas for this this applications?
It is not on the market now. It is planned for Q1 2015
Any thoughts on the theory behind it?
Particularly in comparison to the traditional rectangular sectors.
It is just a plain and simple horn antenna. These where commonly used as exciters in prime focus satellite antennas years ago.
Basically, a microstrip array panel as those used in the sectors is a more modern concept.
And building a sector with a similar pattern is no big deal either. Just that no one needs a sector like that.
Would you use it in place of the traditional sector antennas?
That depends on what I would try to achieve.
If I need multiple clients in a small angular region (less than 60 dgr) at greater distances (2-5 km), I would choose a sector.
For a greater than, let’s say, 60 degrees angle at relatively great distances, that’s a job for multiple sectors.
Of course, a single client far away, that’s the job of a dish.
For many clients which are quite near, let’s say less than 2-3 km, an omni antenna would do.
And a lot of clients at variable distances, well I think this is the place for some antennas with lower gain and worse directivity, like the ones in the pdf.
But any low gain outdoor panel would give the same. But sectors, if you give it a few degrees downwards tilt to cover the clients just next to the tower, would also do a good job.
So I think it just comes down to a single question: What’s the price compared to a wide angle sector?
Other things that come to mind: Are they dual polarity?
And an issue not to be neglected: Horn antennas, which have that hole in the middle, tend to collect spiders, small hornet nests and other insects. So unless there is some kind of randome for them, some maintenance could be required.
Very helpful information.
The next question here is:
What brand (or even model) are you guys using now for this type of application (i.e. PtMP 2-3km)?
What’s tried and proven? 
Where is the benefit of this over a standard panel antenna as a sector?
Maybe this will surprise me, but I don’t see the gap in the market this is suppose to fill.
When co-location interference is a big issue on a busy mast then any antenna even with reduced horizontal coverage will help.
This will definitely occur until as mentioned a cover is placed over the horn antenna, Well done for pointing this operational issue out.
They will come with a radome, but this isn’t mentioned in any of the publicly available information about these units.
Where is the benefit of this over a standard panel antenna as a sector???
The radiation pattern is “different”, not necessarily “better”. Choose the antenna that has the radiation pattern [amongst other characteristics] appropriate to the scenario.
If anyone interested, i’ve been on a demo day where RF Elements shows they new products.
Those simper sectors are “symmetrical antennas” what means, both vertical and horizontal gain and direction are the same.
Yes, they are MIMO antennas. What is really good: they (will) have direction connection to radio, and not need any RF cable (nor pigtail).
The radio will easily mounted on antennas backside.
Also, thanks to the design of antenna, there will be no sidelobes, also back radiation is minimized.
The smallest beamwidth will be around 30degrees. That means (if you properly shield the radio box) you can setup 12x30deg antennas, without interfering your other sector.
Or you can setup 2 different “rings” of 60deg sectors. Upper ring serving far customers, lower ring serving nearby customers.
If you can push ~80mbps/sector that can be 2x6x80 = almost a gigabit from a single site!
What i really wait is their high gain directional antennas - they promise better isolation than Jirous extreme antennas.
What’s the release date?
In fact it is nothing but a horn antenna.
I do not understand why someone would at this sector to radiate equally in both planes.
That would mean that interfere strongly with other antennas located above and below this type of antenna
I’d be really curious to see how they can get more than -53dB separation between polarizations.
Why do you think, it will interfere with other antennas, because of the radiation pattern?
This antenna is a waveguide (correct me if needed).
There will be two versions: standard, when you connect your radio’s RF connector directly to the horizontal and vertical dipol
or modified radio, when the radio has no RF connector, but the RF connector got replaced with properly mounted horizontal/vertical dipol.
If you look into the attached radio box, it have two dipoles inside (as feeder for the waveguide).
About the isolation: i cannot tell you anything about the isolation between the two polarities, but as saw the antennas in the real world, i understand why it can resist interference from antennas NOT directly in the main beam. The antenna is made of metal, so that isolates from the direction coming from side, and the internal pattern isolates the signals coming from out out main direction.
The above things are NOT valid for traditional sector antennas.
Yes it is a waveguide with a corrugated horn. This type of horn antenna has a radiation that looks like this and is especially suitable for point to point links
horn_directivity.JPG
An antenna sector radiation should look like this:
sectoral horn patern_1.JPG
As shown vertical radiation is greatly attenuated.
In the idea of this discussion , any panel or parabolic antenna can be considered as a sector antenna because the radiation is similar in the two plans.
I think, choice of sector is depends on the specific environment.
For example in my situation, in noisy urban environment i don’t mind if if the same direction is covered by two sectors, because that means,
the customers can share on bigger bandwidth.
Also, i understand your point, that you CAN cover the same area with a sector antenna what has different radiation pattern on horizontal and vertical direction (i not mean H/V polarity!). But bigger openin in antenna means not only bigger coverage, but bigger noise to!
But bigger openin in antenna means not only bigger coverage, but bigger noise to!
At this point I agree with you