If you are contemplating building a horn antenna like in the reference. There is some design information in this file
http://barry.sarcasmogerdes.com/qb64...ttenuators.zip
The source code is in BASIC modified for QB64(gl). The exe files are compiled with QB64(gl) and will run on a 64 bit computer. I have had the BASIC source for 30 years but could never get the Horn.exe it to run properly. It took me two days to debug and find the very simple syntax error
Barry