10GHz ATV is easy
https://hackaday.com/2016/12/22/get-on-10-ghz-for-3-euros/
http://www.pe1rki.com/dro.html
https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fhome.deds.nl%2F~knol%2FHB100%2F&edit-text=
Excellent article...
http://f6hcc.free.fr/10ghz.htm
https://translate.googleusercontent.com/translate_c?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&sp=nmt4&tl=en&u=http://f6hcc.free.fr/10ghz.htm&usg=ALkJrhjYz3gVg1-PzYiJf4r-a7iJMt9sWQ
http://www.ham-radio.com/sbms/presentations/Walt_Clark/DROplexer.pdf