Simple introduction of SMA RF connector

SMARF ConnectorAs an important electrical connection component, it plays an important role in various electronic equipment, instruments and electronic information systems. After decades of development, RF coaxial connectors have formed an independent and complete professional system and become an important part of the connector family. The rapid development of the domestic information industry has strongly driven the continuous growth of the RF connector market.

In addition to the pursuit of miniaturization and high frequency of these two key technology projects, RF coaxial connector manufacturers are also in the product's multi-function and reliability of continuous improvement. Now the RF connector in addition to the role of signal connection, but also has the function of processing signals, such as filtering, phase adjustment, mixing, attenuation, detection, limiting and so on. In addition, low standing wave, low loss, large capacity, high power and ease of installation have also become the goals of manufacturers. "With the change of the production process, stamping technology has now appeared. In the past, it was turned. Now it is formed by stamping once, so that the volume can be made smaller, and the height of the entire connector is less than 2 or 3 millimeters. Now some coaxial connectors have been made as small as sesame.

Basic parameters of SMA connector:

The insulation resistance refers to a resistance value exhibited by applying a voltage to an insulating portion of a connector to generate a leakage current in or on a surface of the insulating portion. It is mainly affected by insulation materials, temperature, humidity, fouling and other factors. The insulation resistance value provided on the connector sample is generally the index value under standard atmospheric conditions. Under certain environmental conditions, the insulation resistance value will decrease to an unnecessary extent.

(I) safety parameters

The insulation resistance refers to a resistance value exhibited by applying a voltage to an insulating portion of a connector to generate a leakage current in or on a surface of the insulating portion. It is mainly affected by insulation materials, temperature, humidity, fouling and other factors. The insulation resistance value provided on the connector sample is generally the index value under standard atmospheric conditions. Under certain environmental conditions, the insulation resistance value will decrease to an unnecessary extent. Also pay attention to the test voltage value of the insulation resistance. According to the insulation resistance (MΩ)= voltage applied to the insulator (V)/leakage current (μA), different voltages are applied, and the results are not used. In the test of the connector, the applied voltage is generally 10V,100V,500V three gears.

(II) withstand voltage

Withstand voltage is the critical voltage between the insulated parts of the contact pair or between the insulated parts and the ground, which can withstand higher than the rated voltage within a specified time without causing breakdown. It is mainly affected by the contact pair spacing and creepage distance and geometry, insulator material, ambient temperature and humidity, and atmospheric pressure.

(III) flammability

Any connector can not be separated from the current at work, which there is a risk of fire. Therefore, the connector is required not only to prevent ignition, but also to self-extinguish in a short time upon ignition and fire. In the selection should pay attention to choose the use of flame retardant, self-extinguishing insulation materials of electrical connectors.

Terminating Method of SMA RF Connector

1. Wiring type

Wiring is divided into wire and crimp connectors. The welding wire type is to weld the center conductor and the cable shielding layer. Crimping type is to crimp the center conductor and cable shielding layer, and the pressing type has good efficiency and high performance. The wire bonding type is stable and reliable. Generally, flexible cables are mostly pressed and pressed, and semi-flexible cables and semi-steel cables are mostly welded.

2. PCB (printed circuit board)

When the connector is to be connected to the PCB, it is mostly a plug-in type (Through Hole) or a patch type (SMT). In order to easily tin, and PCB connection metal is mostly gold plated or tin plated.

3. Panel type

Panel connectors are mostly installed on the chassis to connect internal and external devices. The flange type is fixed by drilling on the connector body panel. There is also a screw on the connector body, fixed with the screw. Such connectors often also require a waterproof function.

The development trend of SMA RF connector will have the following characteristics:

1. Miniaturization of SMA RF connector: With the miniaturization of the whole system, the volume of RF connector is getting smaller and smaller, such as SSMB, MMCX and other series, the volume is very small.

High frequency of SMA RF connectors: HP in the United States has introduced RF connectors with a frequency of 110GHz a few years ago. The use frequency of domestic general products does not exceed 40GHz. The frequency of use of flexible cables does not exceed 10GHz, and that of semi-rigid cables does not exceed 20GHz.

3, SMA RF connector multi-function: in addition to the role of bridge, both signal processing functions, such as filtering, phase adjustment, mixing, attenuation, detection, limiting, etc.

4, low standing wave, low loss: to meet the needs of weapon systems and precision measurement.

Large capacity and high power of SMA RF connectors: large capacity and high power are mainly adapted to the development needs of the information superhighway.

6, surface mount: mainly adapt to the development needs of SMT technology (surface mount technology), and is conducive to simplifying the wiring structure design of multi-layer printed board.