A radio frequency (RF) system including: a first conductive covering surface, a portion of the first conductive covering surface including a portion of the first outer wall of a first RF device; a second conductive covering surface aligned to the first conductive covering surface, the second conductive covering surface being disposed around the insulating hole; an insulating hole for an RF center conductor extending through the first conductive covering surface and the second conductive covering surface, the first conductive covering surface and the second conductive covering surface being disposed around the insulating hole; a cavity bounded by the first conductive covering surface and the second conductive covering surface, the cavity being an insulating region; and an RF signal pickup disposed within the cavity.