Balun Design for Satellite Radio cabling?

[Pogostik]

I have a need to use some existing 75-ohm RG-6/U coax wiring in an installation to connect to a Sirius Satellite Radio antenna. Sirius operates on 2.4GHz and uses a smaller 50 ohm coax and SMB connectors. The RG-6/U cabling in the building was originally installed for satellite cable television and was never used. I would like to be able to use this existing wiring to connect a Sirius antenna on the roof (50 ohm to 75 ohm) and then convert the signal back to 50 ohms in the destination office.

I'm concerned about the signal loss at both conversion points. I'm thinking that designing a PCB printed balun circuit with appropriate connectors would be the best solution. Has anyone designed or worked with baluns for a similar purpose? I'd appreciate any assistance or direction to other resources on this topic.

 

[bobatious]

This is a very common balun type, usually used to connect a half-wave dipole with nominal 75ohm impedence to 50ohm downfeed. Just make sure the balun is designed to work at these high frequencies.

Two of these will do the job nicely. The loss per balun is only a db or two; probably negligible. More interesting losses will occur in the cable if you are really passing 2.4GHz RF directly, and the cable is more than a few feet long. If total loss is an issue you could amplify at the head (antenna) end in typical fashion, with various off the shelf parts.