The BNC connector is a connector type, quick connect/disconnect, incoporando more security connector for coaxial cable. Initially designed as a miniature BNC Connector Type C is a type of connector used with coaxial cables like RG-58 and RG-59 RF applications that required a quick connector, suitable for UHF and constant impedance to over a wide range.

The impedance (Z) is a measure of opposition that a circuit to a current when a voltage is applied. The impedance extends the concept of resistance circuits alternating current (AC), and has both magnitude and phase, unlike resistance, which has only magnitude. When a circuit is powered with direct current (DC), there is no distinction between the impedance and resistance; the latter can be thought csa impedance with zero phase angle.