Funk means RF/radio/wireless. The term originates from the first radio transmitter ever, which used spark gaps (spark = Funke, gap = Strecke/Spalte) to generate

Funk means RF/radio/wireless. The term originates from the first radio transmitter ever, which used spark gaps (spark = Funke, gap = Strecke/Spalte) to generate detectable RF. So German Funk is actually directly related to the English funk (as in music) etymologically.