directional coupler

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bobytronic

Joined: 22 Sep 2003
Posts: 47

17 May 2004 17:28 directional coupler

Hi,

I'm searching a 4 ports directional coupler with the following specifications:

Input Power : up to 30W
Frequency : between 800Khz and 4Mhz

Someone can give me a surface mount component reference or a manufacturer or a schematic ??

Best Regards.

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flatulent

Joined: 19 Jul 2002
Posts: 4875
Helped: 324
Location: Middle Earth

17 May 2004 17:51 Re: directional coupler

With this frequency range you would need a two transformer type. With your 30W power requirement, it is unlikely that this would come in surface mount because of the large size and weight. Vibrations would rip it from the board.

Here is a design program. You should do a SPICE simulation to make sure the values you select work over the frequency range you want.

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radiohead

Joined: 13 May 2004
Posts: 412
Helped: 34
Location: Heart of Europe

17 May 2004 22:13 Re: directional coupler

Flatulent,

Any ideas for a wideband directional coupler from 10MHz to 1.5GHz ?

flatulent

Joined: 19 Jul 2002
Posts: 4875
Helped: 324
Location: Middle Earth

17 May 2004 23:09 Re: directional coupler

radiohead wrote:

Flatulent,

Any ideas for a wideband directional coupler from 10MHz to 1.5GHz ?

If you are willing to have a drastically variable coupling factor, the two transmission line type will work. The coupling at frequencies less than a quarter wave length is the sine of the length in degrees times the maximum coupling.

Another option is to have two couplers in tandem and have them optimized for different frequency ranges.