Many, many years ago, I could often be seen out on the street with a tripod with a dish on it, looking like some crazed mad scientist come super spy. This was me testing the setup of a 10GHz WBFM system I had got from Eric G0PAQ. This was based on the old Gunnplexor x-band doppler radar modules, as used to open supermarket doors.
Gunn diode based FM systems have long been obsolete, most microwave enthusiasts now having moved onto BUC/LNB based SSB systems. But, FM was at least fun.
Gunn diode units are rare and expensive now. But why not still play with 10GHz FM? Especially when you can get these
Who knows, perhaps SOTA 10GHz WBFM might make a comeback!