Various Coaxial Connectors

Coaxial connectors are used to transmit radio frequency signals. The transmission frequency range is very wide, which can be up to 18GHz or higher. Coaxial connectors are mainly used in radars, communication, data transmission and air equipment. The basic structure of coaxial connectors includes: the central conductor (positive or negative central contact); the dielectric material or the insulator outside the inner conductor; the outer contact. The outermost contact plays the same role as the outer shielding layer of the coaxial-cable, i.e. transmitting signals and acting as the shielding or grounding element of the circuit.

Coaxial connectors are mainly divided into SMA, SMB, BNC, TNC, SMC, N type, BMA, etc.

Male: The thread is inside the male (plug), and there is a needle in it, such as TNC (M).

Female: The thread is outside the female (socket), and there is a hole in it, such as SMA (F).

RP: Reverse

Polarity means that the head is opposite to the needle inside.

Bulkhead: It means that the joint of the lockable screw on the board containing spring washer, screw cap and retaining wall (SMA FEMALE BULKHEAD).

PCB: It refers to a joint with feet and it can be soldered to the board (such as SMA FEMAL PCN ).

Panel: It is a joint with screw holes and it can be locked on the board with screws (such as SMA PANEL MOUNT). Generally, there are 4-hole and 2-hole types of panels.

1. SMA

SMA series connectors are extensively used coaxial connectors that are connected by small screw threads. They have excellent service life and performance as well as high reliability, and microwave equipment and digital communication equipment widely adopt the military grade connector to receive the radio frequency back to the coaxial cable assemblies or micro-strips.

In wireless devices, they are commonly used for the clock interface of GPS on single board and the RF module of the base station.

2. SMB

SMB coaxial connectors are small push-in and locking RF coaxial connectors, which have the characteristics of small volume, light weight, convenient use and excellent electrical performance. They are suitable for connecting the coaxial cables in high-frequency circuit of radio equipment and electronic instruments.

In wireless equipment, they are often used to connect E1 transmission cables of the base station with DDF small transmission boxes of the base station.

3. BNC

BNC coaxial connectors are bayonet RF coaxial connectors, which have the characteristics of quick connection and reliable contact. They are widely used to connect RF coaxial cables in the field of radio equipment and electronic instruments. In wireless applications, they are commonly used as military cable connectors of wireless test instruments.

4. TNC

TNC coaxial connectors are screw thread RF coaxial connectors, which have the characteristics of wide working frequency band, reliable connection and good seismic performance. They are used to connect RF cables in radio equipment and instruments, especially in mobile communication equipment under vibration conditions.

5. SMC

SMC coaxial connectors are small threaded RF coaxial connectors, which have the characteristics of small volume, light weight, good seismic resistance and high reliability. They are used to connect RF coaxial cables in radio equipment and instruments, but they are less used in our devices.

6. N type

N type series coaxial connectors are medium and high power connectors with the threaded connector structure. They have the characteristics of strong seismic resistance, high reliability and excellent mechanical and electrical performance. They are widely used for connecting RF coaxial cables in radio equipment and instruments under vibration and harsh environment.

They are commonly used as the military grade electrical connectors for GPS antenna feeders, RF connection of RF modules, lightning arresters, power dividers, combiners, etc.

7. DIN type

DIN type (also known as 7/16 or L29) series coaxial connectors are connectors connected by large screw threads, which have the characteristics such as strong stability, low loss and high working voltage. Most of them have the waterproof structure, so they can be used outdoors as medium and high energy transmission connectors. DIN coaxial connectors are widely used in microwave transmission and mobile communication systems.

They are commonly used as antenna feeder connectors and antenna terminals in base stations.

8. The coaxial terminal

The coaxial terminal load is used for the end connection of coaxial transmission system, and it is generally used for the system test of RF signal transmission. It has the characteristic impedance matching with the transmission line, and is also the absorber element in the system. The characteristic impedance is 50 OHM and 75 OHM respectively.