Selection of common coaxial connectors

- Dec 03, 2018-

BNC is a mount type, mostly used for RF connections below 4GHz, widely used in instrumentation and computer interconnection.

TNC is a threaded connection, size and other aspects similar to BNC, operating frequency up to 11GHz, threaded type suitable for vibration environment.

SMA is threaded connection, the most widely used, impedance has 50 and 75 ohm two, 50 ohms when the use of soft cable frequency is less than 12.4Ghz, with semi-rigid cable up to 26.5GHz.

SMB volume is smaller than SMA, for the insertion of self-locking structure, for fast connection, commonly used in digital communications, is the replacement of L9, 50 ohms can reach 4ghz,75 ohm to 2GHz.

The SMC is threaded, and other SMB-like, has a wider frequency range and is commonly used in military or high-vibration environments.

N-type connector for threaded, air as an insulating material, low cost, frequency up to 11GHz, commonly used in test instruments, there are 50 and 75 ohm two.

The MCX and MMCX connectors are small in size and are used for intensive connections.

The BMA is used for blind plug connections of low-power microwave systems with frequencies up to 18GHz.

Each connector has military and commercial standards, military standard according to mil-c-39012 manufacturing, all copper parts, PTFE insulation, internal and external gold plating, the most reliable performance, but the cost is higher.

Commercial standard design uses cheap materials, such as brass casting, polypropylene insulation, silver plating, etc., the reliability is less. Connector materials are brass, beryllium copper and stainless steel, central conductors are generally gilded, to ensure low resistance and corrosion resistance.

Military labels require gilded on SMA and SMB, silver plating on N, TNC and BNC, because silver is easy to oxidize and users prefer nickel plating. Insulation materials have PTFE, polypropylene and toughened polystyrene, of which PTFE insulation performance is the best, but the cost is higher.