This scheme is an SWR meter, which is quite simple and easily built. Once you make a directional coupler, the results will be displayed with the measure led meters as a ratio SWR.
C used in the scheme SWR meter is an LM3914, which are available on the market. Use non-inductive resistor (carbon-film or metal-oxide).
Complete set of SWR protection circuit schematic, see example image below to prototype soldering its components and the layout..