RF interference choke device and RF testing apparatus incorporating the same

A radio frequency (RF) interference choke device includes a planar dielectric board formed with two first slots and two second slots that extend in a lengthwise direction of the dielectric board. The first/second slots are arranged symmetrically about a central line of the dielectric board parallel to the lengthwise direction, and have a first/second length associated with a first/second frequency band. A metal layer is attached to the dielectric board, and has a U-shaped first pattern surrounding the first slots, a U-shaped second pattern surrounding the second slots, and a strip-shaped third pattern extending along the central line and interconnecting the first and second patterns.