Differential to single end converter

Besides balun, anyone knows how to design differential to single end converter? it works at 5GHz.

Following paper is attached for your refernce. It shall give you lot of usefull information. It is highly informative.

I have read that paper. I do not believe that is a good solution. Thanks anyway

try with this circuit, its output is proportional to the difference between inputs.

Thanks STOIKOV. However, if it works at 5GHz, you will find it maybe not good. Thanks anyway