How to combine 4 Fm channels in to one common antenna

[aneesholv]

Hai

In my common Tranmission infrastructure ( FM radio Transmission unit ) there are 4 FM channels( each have 5 KW power) including my FM station .Here I want to know How can These 4 FM channel combine in to a single stream for broadcast through a common antenna system ? Can You explain the working of these combining system and antenna ?

Regards
Aneesh

 

[biff44]

I am not an expert I such high powers, but I believe the do this with a 4 filter quadraplexer. The filters are physically big, due to the need for high Q resonator elements.

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I am not an expert I such high powers, but I believe the do this with a 4 filter quadraplexer. The filters are physically big, due to the need for high Q resonator elements.

 

[BigBoss]

I guess these kind of power transponders are combiner with Waveguide Combiners.Otherwise standard circuits and Microstrip Structures/Coaxial Elements can not support these power levels.
It's just a guess..

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I guess these kind of power transponders are combiner with Waveguide Combiners.Otherwise standard circuits and Microstrip Structures/Coaxial Elements can not support these power levels.
It's just a guess..

 

[chuckey]

Wave guide combiners are HUGE at these frequencies ? 3m X 3M cross section. A better way would to use resonant acceptor/rejector cavities with special lengths of coax between them which if long enough would give a "comb" filter, nulling out multiple channels.
Frank

 

[BigBoss]

**broken link removed**