One antenna double radios

I am curious about this, but please forgive me if I am stupid.

I was thinking if I bought an antenna, for example radiowavs SPD4-5.2 which supports frequency from 5.2 GHz to 5.8 GHz. Can I hook 2 radios of different bands in the same antenna, ie a radio in 5.4 Ghz and another one in 5.8 GHz. I have done this setup in Satellite SCPC scenario with IF combiners and dividers. But I wonder if it could be done with canopy OFDM backhaul radios. The reason I am asking is because I could do away with additional antennas and would require less tower space.

Yes it can be done. Andrew and Radiowaves has dual input antennas, Horizontal and Vertical. That’s the best option because you will not have the insertion loss using the coupler or splitter ( In this case 50% of the power is splited and less the insertion loss of the coupler ~3dbm).

You will be point in the same direction for the 2 links, and you can’t be off the the amount of arperture of the beam of the antenna ( 2-8°).

I was wondering if this could be done for BH150/300 as well, where the radios use both the polarisation. I heard BH150/300 use both polarization and which can be done via dual-pol dish. I was wondering if I could run 2 BH150/300 from the same dual-pol antenna, if one radio was in 5.4 and other in 5.8 GHz.

I have done the calculations using the link estimator and it seems that I might need to run double radios for the data rate I am planning. The tower space is problem, because I am not allowed to build a big tower due to some regulatory issues.

let me get this straight… (I am new to connecterized antennas)

If I have an Orthogon 5.4 link, with 3ft bi-polar dishes on both sides, are you saying I can also run a 5.7GHz link using the same dishes ?

I am asking if I can run it. In VSAT we could.

You need to combine the RF from the two radios onto one connector using an RF combiner rated for the frequencies you are using. … 6+Combiner

To get creative,
Let’s say you have a 900 radio running at 906MHz co0nnected to an omni and it’s covering your area fine, but you wanted to increase the capacity of the coverage area.

You could add another 900 radio at one of the non-overlapping freqs like 915 or 924, and use a combiner to feed the two radios into the omni antenna. You will lose about 1dB from each radio, so someone on the fringe might drop off and need a bigger antenna, but you will effective double the capacity without the need for another 1000.00 horizontal omni antenna.

Jerry, VJ and nepalken,

On 900 MHz it gets more complicated. The RF power is higher and the units do not have very good bandpass filters ( If any ).
It only take a few minutes to see what a real spectrum analyzer show and what the 900 MHz canopy show. A regular phone, cordless in the 900 that only uses 12KHz of rf bandwidth will show on the 900 MHz canopy spectrum as a 5 MHz slot. That show that the receptor is not filtered and it’s not discriminating. These filter used to be big but now they are smaller about 6 or 12 inches.
In this case you will need the CMM to synchronize the transmission but the reception could get ugly.
One could get filters to do this but you will lose more than 1 db.

Now, on microwave it could be done but it would be nice to use filters. Problem is that the receiver will have high power reception or Reverse power. This could cause some damage at the end. But the specs ( IEEE ) tells that the receiver should be able to receive a 0 db load with out damage to the circuits. ( That is very good )

If you do it on 5.x try to leave a 20MHz unused channel space.

this company has low cost multiplexer available but only in the 2.4 GHz, who knows, maybe they could make one in 5.x GHz.

I have to stop assuming that everyone uses sync. ridnet is right, the only way stacking would work is if the APs are sync’d

This is the link for the multiplexer.

It’s expensive!

Why would you want to run a set of 5.4 150’s and a set of 5.8 150’s on the same dish? I see no logic to this. If capacity is the issue use a single set of 300’s otherwise if you can afford to run 2 sets of 150’s on your link you should share the love.

attitude is correct.

doesn’t make sense to run 2 x 150 ODU’s when it is cheaper to upgrade from 150 to 300.

I would like to do it for two reasons, use a different band (redundancy) and secondaly tower space…

many links and new gadgets mentioned… I have reading to do… I can’t get a standard connecterized to work at the moment


I agree upgrading to 300 would be cheaper and more logical than trying to run two 150.

I have limited tower space and I have done the calculations using motorola’s link estimator with different size antenna. As the distance increase, the throughput decreases. I have to do either of the following if I want to have a better throughput.

1. Increase antenna size
2. Break the hop to decrease the distance
3. Use an additional pair (radios and antenna).

1 and 2 are beyond my control, so the only logical thing would be option 3.

VJ what do you mean you can’t get a standard connecterized to work? Maybe I can help.

Had nothing to do one day so I decided to take apart a Integrated 60Mbps BH who knows why. right on the back of the int antenna was a sticker with MTI wireless edge and part no#. MTI is an Israeli company imported by several US distributers. Most of Teletronics panel antennas are made by MTI. If you look on their site they have several 5.7Ghz antennas with or without housings. The housing is similar to the original 45Mbps BH and the mount is identical. Anyway let me get back on track. Teletronics does not have the dual pol 23dbi unit that comes on the OFDM radios listed on the site, they just have one that will do ver or hori pol. It is listed on MTI’s site. I called Teletronics and they ordered me a few sets with and without housings. Took a little time sitting on the docks waiting to go threw customs but I wasnt in a hurry. I just got done installing 2 5.7Ghz 20Mbps BH’s inside the housing. One vertical and one horizontal. Ill fire them up Monday and test them. If all works well I should get double the threwput and if one BH fails the link should drop to half speed and keep on truckin.

Hay nepalken how long a shot and how much capacity do you need? What do you consider limited tower space? FYI I have a 79 mile shot using 4ft dishes 60Mbps BH’s on both ends running at 64 Quam 7/8 full duplex.

One last thing. I did think of a good reason instead of upgrading. If you wanted to run dual 60Mbps BH’s for added capacity but wanted to stay, or had to stay with 20Mhz channel spacing instead of the 30Mhz on the 150/300’s.


The distance is 72 km and I need 150 Mb duplex for internet and about 60 mbits for PCM E1.

mmm… off to study…


It can be done.
Can you do with several channels circuits, ie 4 DS3?