27 Mhz directional coupler
thanks in advance
You can search between numerous ham projects on the web. Search for swr meter.
Search google for high power lumped directional coupler.
It gives about 670 scores, and about a few ten useful too.
g579
I remember there was a classical article on one issue of RF Design 1989.It introduced a high power directiomal coupler based on traditional transformer tech binded with stripline tech.It can get as high as 50dB directivity.
THE directivety is the most difficult thing to make
Quote from the article:
"The configuration used in the Tandem Match works well over the frequency range of 1.8 to 54 MHz, with a nominal coupling factor of 30 dB. Over this range, insertion loss is less than 0.1 dB. The coupling factor is flat to within ±0.1 dB from 1.8 to 30 MHz, and increases to only ±0.3 dB at 50 MHz. Directivity exceeds 35 dB from 1.8 to 30 MHz and exceeds 26 dB at 50 MHz."
yeap .. i can confirm this principles works fine .. we are using severel of them for ham radio use for long time with several kw power thru it ;0))
regards
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