This edition of ANSI C63.7 extends the application of the document to use above 1 GHz extending up to 18 GHz and is thus applicable for the use with ANSI C63.4. While there is no site validation method available above 18 GHz, the changes are considered appropriate guidance for use up to 40 GHz. As construction guidance is different in some cases for sites below 1 GHz and for sites above 1 GHz, the material is broken into clauses that apply to these two frequency ranges and the most used test facilities. Where the same guidance holds and is frequency independent, that guidance will also be in an introductory clause to the provisions for both frequency ranges.