A radio-frequency connector consisting of a socket member and a plug member electrically connectable to the socket member is disclosed. The socket member or plug member has an impedance element mounted therein such that the impedance element is electrically connected to the metal casing and metal center pin of the socket member or plug member that carries the impedance element when the plug member is disconnected from the socket member, causing the impedance element to provide a terminal effect to insolate external electromagnetic noises; the impedance element is separated from the metal casing and metal center pin of the socket member or plug member that carries impedance element when the plug member is connected to the socket member.