What Is an RF Connector?

RF Coaxial Connecter

RF and wireless systems are used extensively in virtually every modern application. Hence, there are a wide array of different types of RF Connectors to provide interconnect between modules and systems either via board-to-board, board-to-cable, or module-to-board connections. RF connectors are the physical piece of equipment that is used to provide a convenient and standardized method of interconnect at a node, as opposed to making a direct crimp, solder, or clamp connection at port. The difference between an RF connection at a node or port and an RF connector, is that a connector is a distinct physical element (electromechanical device) designed to make an electrical connection and break an electrical connection between two different circuits using a separable interface.

RF connectors, mainly RF coaxial connectors, are the most commonly used type of RF connectors and provide a relatively quick and reliable method of making an RF interconnection while introducing minimal signal degrading characteristics. As there are such a wide variety of interconnect requirements in RF systems, there are also many varied types of RF connectors. RF coaxial connectors come in many standardized types, which is a legacy of their innovation for military/defense applications. The most common types of RF coaxial connectors are SMA, N-type (such as N Male Low PIM Connector), BNC, MCX, SMC, 3.5 mm, and D-Sub coaxial connectors. There are many others including variations that are specifically designed with enhanced feature sets. An example of this is Low passive intermodulation (PIM), High Voltage (HV), oil/gas rated, plenum, quick connect/push-fit/snap, bayonet style, precision/high precision, and a range of different types of ruggedized connector variants. Among the many coaxial connector variations are also proprietary and application-specific types, such as NEX10 Connectors, and FAKRA connectors, which are mainly used in automotive.

RF coaxial connectors are all made of a center pin, dielectric spacer, and outer conductive housing. The center pin acts as the center conductor and includes a method of attachment to either a cable, wire, or board contact. The dielectric spacer helps to control the impedance of the coaxial transmission line and ensures coaxiality between the center pin and the outer conductive housing. The outer conductive housing acts as the outer conductor, electromagnetic shielding, and as environmental protection. The outer housing of the coaxial connector also acts as the means of mechanical connection, and includes some type of alignment and retention mechanism, be it threaded, bayonet, or some type of push, snap, press-to-connect, or spring force mechanism