RF connectors summary

RF coaxial connectors are used to transmit radio frequency signals, and their transmission frequency range is very wide, up to 18GHz or higher. They are mainly used in radar, communication, data transmission and aerospace equipment.

The basic structure of a coaxial connector includes: a center conductor (a male or female center contact); a dielectric material outside the inner conductor, or an insulator; The same role as the shielding layer, that is, to transmit signals, as a grounding element for shielding or circuits.

RF coaxial connectors can be divided into many types, the following are the common types:

1.N type connector

Type N connector (Type N connector), which is threaded and can be locked by rotation. It was one of the first connectors capable of transmitting microwave frequency signals and was invented by Paul Neill of Bell Laboratories in the 1940s and named after Neill's initials. The signal frequency range supported by the N-type connector is 0 to 11GHz, and the enhanced type can reach 18GHz. There are two types of characteristic impedance, 50 ohms (widely used in mobile communications, wireless data, paging systems, etc.) and 75 ohms (mainly used in cable TV systems).

2. BNC connector

The BNC connector is also one of the radio frequency connectors that are often seen. It is a small bayonet connector that can be connected quickly. This connector shape), the original meaning of BNC (Bayonet Neill–Concelman) actually comes from the initials of the surnames of two inventors, Paul Neill and Carl Concelman, Paul Neill is also the inventor of the N-type connector. BNC connectors are widely used in wireless communication systems, televisions, test equipment, and other radio frequency electronic equipment. Early computer networks also used BNC connectors. The signal frequency range supported by the BNC connector is 0 to 4GHz. There are two types of characteristic impedance: 50 ohms and 75 ohms.

3. SMA connector

SMA connector is a widely used coaxial connector with small threaded connection. It has the characteristics of wide frequency band, excellent performance, high reliability and long life. SMA connectors are suitable for connecting radio frequency cables or microstrip lines in the radio frequency circuits of microwave equipment and digital communication systems. They are often used for GPS clock interfaces on single boards and test ports of base station radio frequency modules on wireless equipment. The full name of SMA is SubMiniature version A, which was invented in the 1960s. The signal frequency range supported by the SMA connector is from DC to 18GHz, and some types can support up to 26.5GHz. The characteristic impedance is 50 ohms.

4. SMB connector

The full name of SMB is SubMiniature version B. It is a small push-in locking RF coaxial connector. It has the characteristics of small size, light weight, convenient use, and excellent electrical performance. Used for connecting coaxial cables in the loop. It is often used on wireless devices to connect the E1 transmission cable on the base station side to the DDF small transmission box of the base station. SMB connectors were invented in the 1960s and are smaller in size than SMA connectors. There are two types of characteristic impedance: 50 ohms and 75 ohms. It has excellent electrical characteristics in the frequency range from DC to 4GHz. SSMB is a miniature version of the SMB connector that can support up to 12.4GHz.

5. SMC connector

The full name of SMC is SubMiniature version C, which is also a radio frequency coaxial connector invented in the 1960s. It features a #10-32 UNF threaded interface and provides excellent electrical performance from DC to 10GHz. SMC males have external threads and SMC females have mating nuts. There are two types of characteristic impedance: 50 ohms and 75 ohms, which provide interconnection methods for small coaxial cables and printed circuit boards where size is very important.

6. F-type connector

The F-type connector is a radio frequency connector that everyone will see in our daily life. It is widely used in the fields of cable TV, satellite TV, cable TV modem and TV. It can be used in places where impedance matching is required, and it can also be used in non-matching places. It is characterized by threaded connection and easy mating. Stable performance. Invented by Eric Winston in the early 1950s, the F-connector became a common VHF TV antenna connection in the United States in the 1970s. The price of the F-type connector is very low, the characteristic impedance is 75 ohms, and the highest frequency can generally be supported to 1GHz or 2.4GHz.