Frequency Diversity with single antenna

[mohamad]

Dear all friends,
In a MW radio link with 1+1 FD configuration, is it possible that antenna directly connect to ODUs without use of flexible waveguides? The antenna is dual polarized but in this link, two frequency channels are transmitted via same polarization.
Please note that in 1+1 HSBY, output of ODUs is fed to hybrid kit and then hybrid kit will connected to antenna. actually ODUs are integrated to antenna.
Is there any technical problem in antenna integration with ODUs in FD configuration?

Regards,

Mohamad

[moya]

Mohamad,

As far as I know there is no cost effective way to separate the frequencies from a FDD system. I know this is not what you asked, but why would you want to split the frequencies given that most FDD system are capped to a max throughput? Are you doing this so you can replace the integrated antennae with higher gain ones? If that is the case do keep in mind that most FDD/TDD units are certified as system (i.e. radio & antenna) and deviating from this will tend to get you in troubles with the local regulatory entity (i.e. etsi, fcc, etc...).

Not trying to be a smart ass, just giving my 2 cents.

regards,

-moya

[ivan.makajic]

Dear Mohamed,

Do you have some concrete vendor on mind?

If I understand you, you are asking about some 1+1 FD integrated system ( 2ODU's connected direct to antenna without flexy wg).

Off course you need some kind of hybrid (circulator).

regards

[byja]

It is possible to mount 1+1 FD system directly to antenna via RF coupler or similar equipment. These are examples:

http://tesla.rcub.bg.ac.rs/%7Evmarko37/slike/rfcoupler.jpg

http://tesla.rcub.bg.ac.rs/%7Evmarko37/slike/rfcoupler2.jpg

But this type of coupler, as well as most of the others that I know of, is designed to be mounted onto single polarized antenna. As far as I know there are no couplers (excluding OMTs) which are designed to be mounted directly onto dual polarized antenna. The reason is purely mechanical, different types of antennas, different dual pol feeds and flanges. So you'll need a flexible waveguide.

http://tesla.rcub.bg.ac.rs/%7Evmarko37/slike/rfcoupler3.jpg

[Cost_Reducer]

Gentlemen, :D

i have one possibility for you but i think this isn`t allowed from E*******.
You can take a MiniLink antenna with 2 polarisations. On the back you mount the integration kit and onto this you mount the symetrical coupler with the 2 ODU`s.... :confused::confused:
I have seen 1+1FD systems only in a seperate installation or as a integrated solution like onto this picture. Ceragon 1+1FD System for 18Ghz....2STM1 transmission.

Cheers

[byja]

You can take a MiniLink antenna with 2 polarisations. On the back you mount the integration kit and onto this you mount the symetrical coupler with the 2 ODU`s.... :confused::confused:

Theoretically, you could mount a coupler onto OMT which is mounted onto a dual polarised antena with circular feed. But I think such system would be to heavy for OMT-antenna connection.


I have seen 1+1FD systems only in a seperate installation or as a integrated solution like onto this picture. Ceragon 1+1FD System for 18Ghz....2STM1 transmission.

This is a small picture, but it still looks like sepparated mount, not an integrated one. Couplers are not mounted on the antenna.

[Cost_Reducer]

This is a small picture, but it still looks like sepparated mount, not an integrated one. Couplers are not mounted on the antenna.

Hi byja

you are right, this is a seperate installation of the coupler unit. My faiulure :mad:

To mount the coupler unit onto the OMT is to heavy because there are only 4x10mm screws for fixing the coupler. Ant the weight from coupler and 2 ODU`s is round about 10kg...i mean.

Cheers

[ivan.makajic]

The antenna is dual polarized but in this link, two frequency channels are transmitted via V & H polarization.

This is example of 1+1 FD or 2+0 without flexy wg. Link is on 18GHz 2xSTM1

[Cost_Reducer]

The antenna is dual polarized but in this link, two frequency channels are transmitted via V & H polarization.

This is example of 1+1 FD or 2+0 without flexy wg. Link is on 18GHz 2xSTM1

the good old faulty E******* equipment... :p

Other vendors can transmitt 2xSTM1 over 1 polarisation...only E\\\ use 2 polarisations....;) It seemy that e******* don`t develop the 2 STM-1 transmission over 1 polarisation...so you must use this coupler :-(

[mohamad]

Dear Ivan,
I want to integrate antenna directly to ODUs and the antenna is single polarized. As you say I should use circulator in this case but frequency channels are in 7 GHz band. Can I found a circulator in this frequency band from any vendor?

Thanks,


The antenna is dual polarized but in this link, two frequency channels are transmitted via V & H polarization.

This is example of 1+1 FD or 2+0 without flexy wg. Link is on 18GHz 2xSTM1

[mohamad]

Dear byja,
You are right, for connection between ODUs and dual polarized antenna we should use flexible waveguide. But I want to connect ODUs directly to single polarized antenna. Frequency channels are in 7 GHz band. What is the solution?

Regards,

[Cost_Reducer]

Dear byja,
You are right, for connection between ODUs and dual polarized antenna we should use flexible waveguide. But I want to connect ODUs directly to single polarized antenna. Frequency channels are in 7 GHz band. What is the solution?

Regards,

From which vendor is your equipment and your antenna?

cheers,

[mohamad]

Vendor of radio equipments is SIAE from italy and antennas are from Andrew.

Regards,

[ivan.makajic]

Hi Mohamad,

You can find solution in new thread:

http://www.finetopix.com/showthread.php?p=80669#post80669

Enjoy

Regards