# ePMP 4500 + Dual Horn Antenna compatibility
**URL:** https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200
**Category:** ePMP
**Created:** [April 6, 2023, 12:50pm UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200 "2023-04-06T12:50:06Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@TDJ211](https://community.cambiumnetworks.com/u/TDJ211)
#### Post date: [April 6, 2023, 12:50pm UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/1 "2023-04-06T12:50:06Z")
Is it compatible or will a whole new Dual horn antenna need to be developed?
EDIT: After checking out the pics, it appears the radio is fully integrated into the antenna. Does that mean there’s going to be sacrifices in terms of interference/noise??
EDIT2: Ahhh, there’s a 4500C version. Also its 8x8 so looks like its a definite no in terms of compatiblilty with the existing Dual Horn. Hopefully a new Dual Horn comes along soon for us city folk.
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### Author:  [@SWARG\_ANTENA](https://community.cambiumnetworks.com/u/SWARG_ANTENA)
#### Post date: [April 6, 2023, 8:47pm UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/2 "2023-04-06T20:47:08Z")
what a question?
> [@Searching for Antenna test users](https://community.cambiumnetworks.com/t/searching-for-antenna-test-users/87999):
>
> greetings, we have 4 free slots left for potential candidates that are interested in testing our new Antenna. A short introduction video for potential candidates. [[SWARG - Sector Antenna Test User Video] ](https://www.youtube.com/watch?v=0MkIUVZYbCU) BR, SWARG team
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### Author:  [@Douglas\_Generous](https://community.cambiumnetworks.com/u/Douglas_Generous)
#### Post date: [April 11, 2023, 4:10pm UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/3 "2023-04-11T16:10:49Z")
SWARG aside, just using two dual-horn antennas placed in the correct orientation and spacing will provide the compatibility you need.
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### Author:  [@TDJ211](https://community.cambiumnetworks.com/u/TDJ211)
#### Post date: [April 11, 2023, 4:23pm UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/4 "2023-04-11T16:23:00Z")
Oh wow, interesting. have you tested this yourself?
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### Author:  [@Douglas\_Generous](https://community.cambiumnetworks.com/u/Douglas_Generous)
#### Post date: [April 11, 2023, 4:32pm UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/5 "2023-04-11T16:32:03Z")
Not directly, getting our first 4600C in july (waiting on 6ghz licensing. Canada, eh? ) however 20+ years of RF engineering and my own setups using single horns on e3k APs tell me that it works.
RFE has done a wonderful job of making their dual horn setup just work for 4x4, an 8x8 array is just 2x 4x4 systems in sync. The biggest issue is ensuring that each horn has the correct coverage overlap and still maintaining the physical spacing needed to not create a discontinuous wave front from the antenna array. If one of the antennas is as little as half a wave length ahead or behind the others than you will have troubles so mounting and ensuring that the antenna faces are exactly on the same plane is very important.
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### Author:  [@TDJ211](https://community.cambiumnetworks.com/u/TDJ211)
#### Post date: [April 18, 2023, 1:14am UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/6 "2023-04-18T01:14:28Z")
How would you measure and calibrate that?
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### Author:  [@Douglas\_Generous](https://community.cambiumnetworks.com/u/Douglas_Generous)
#### Post date: [April 18, 2023, 1:38am UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/7 "2023-04-18T01:38:27Z")
To create a unified wavefront, you need to take the wave length of your low frequency and of your high frequency and space the two pairs of horns at an even number of wave lengths apart measured center to center of the antennas. You choose the distance based on the averaged difference between these two frequencies and the chosen center frequency of the channel. You have some wiggle room for error since the difference between 5800 -40 and 5800 +40 (80mhz channel centered on 5800 for reference only) is only a small amount. You can just use your chosen center frequency but then you will have performance issues on frequencies more than 100mhz away, eg planning for 5800 but end up on 5240. So a compromise is needed.
If you use RFE dual horns, you dont have to do the math again for the vertical distance. Do not just copy the horizontal distance off the RFE dual horn, it will not work well. You can copy the difference in alignment of the two horns of a single dual horn and just align the secon pair with the same offset, this will minimize the sector cutoff and allow mu-mimo to see both sides of the AP.
Next you need to make sure your 8 cables are as close to exactly the same length as possible. This is important as the rf wave on the cable has to reach the wave guides at the same time.
The more of an array you build the more work that goes into installing it, but the gains are worth it.
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### Author:  [@SWARG\_ANTENA](https://community.cambiumnetworks.com/u/SWARG_ANTENA)
#### Post date: [April 18, 2023, 7:20am UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/8 "2023-04-18T07:20:56Z")
Bull shit,
You can chose any distance or arangment betwen the antennas!
Due to the way how that radio works its highly recommended to align the antennas in the same direction (sector) or non overlaping (split-sector).
In most cases a horizontal placement of the antennas is the best way to go (grouping is done based on azimut angle).
hire is a web side with a simple example to play with:
> **[CALCULATOR](https://antennaarraycalculator.blogspot.com/p/calculator.html)**
>
> PARAMETERS Frequency: MHz Number of elements: 1 2 3 4 5 6 7 8 9 10 Inter-element distance: mm Antenna e...
by changing the amplitude and phase of the channel a beam stearing is achieved (MU-MIMO)
That also means that the cable length can differ
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### Author:  [@Douglas\_Generous](https://community.cambiumnetworks.com/u/Douglas_Generous)
#### Post date: [April 18, 2023, 12:50pm UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/9 "2023-04-18T12:50:40Z")
Mu-mimo is not beam steering.
The way the radio works is by selective antenna array. Mu-mimo works by taking advantage of the fact that the array has overlap between elements but still has some separation between the center lines of each element. This allows client radios in different antanna elements to be seen separately.
You still need to tune the array so that you can take advantage of the gains of a unified wave front from an in-phase array.
Of course this is a very simplified view of the whole but is still true.
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### Author:  [@SWARG\_ANTENA](https://community.cambiumnetworks.com/u/SWARG_ANTENA)
#### Post date: [April 19, 2023, 8:26am UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/10 "2023-04-19T08:26:54Z")
Sorry, you are right its not beam steering its null steearing
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### Author:  [@system](https://community.cambiumnetworks.com/u/system)
#### Post date: [April 18, 2024, 8:27am UTC](https://community.cambiumnetworks.com/t/epmp-4500-dual-horn-antenna-compatibility/92200/11 "2024-04-18T08:27:15Z")
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