'RF-related' originates from the English abbreviation 'RF', itself from 'radio frequency' ('radio' + 'frequency'), where 'radio' comes from Latin 'radius' meaning 'ray' or 'spoke' and 'frequency' comes from Latin 'frequentia' meaning 'repetition'.

'RF-related' developed as a compound from the fuller phrase 'radio-frequency-related' (adjective formed from 'radio frequency' + '-related') and shortened in technical usage to 'RF-related'.

Initially it described things specifically connected to 'radio frequency' in engineering contexts; over time it has remained focused on that sense but broadened to general technology and regulatory contexts.