Your location:Home   News   The Knowledge of the Window
Introduction and performance analysis of SMA RF Termination
 May 20, 2021|View:691

The SMA RF Termination is a widely used semi-precision, ultra-small RF and microwave connector that is particularly suitable for RF connections in electronic systems with frequencies up to 18 GHz and even higher.The SMA RF Termination is available in various forms, male, female, straight, right angle, bulkhead fittings, etc., making it capable of meeting most requirements. Its ultra-small size also allows it to be used, even in relatively small electronic devices.


SMA RF Termination


A. Introduction of SMA RF Termination

SMA is commonly used to provide RF connections between circuit boards, many microwave components including filters, attenuators, mixers and oscillators. The connector has a threaded external connection interface, the interface has a hexagonal shape, allowing tightening with a wrench. They can be tightened to the correct seal using a special torque wrench, allowing a good connection to be made without over-tightening.

The first SMA RF Termination was designed for 141 semi-rigid coaxial cables. The original SMA connector can be called a minimal connector because the center of the coaxial cable forms the center pin of the connection, eliminating the need for a transition between the coaxial center conductor and the center pin of the special connector.

It has the advantage that the cable dielectric is connected directly to the interface without air gap, and the disadvantage that only a limited number of connect/disconnect cycles can be performed. However, for applications using semi-rigid coaxial cables, this is unlikely to be a problem, as the installation is usually fixed after initial assembly.

Second, the performance of SMA RF Termination

SMA RF Termination is designed to have a constant, 50-ohm impedance at the connector. SMA connectors were originally designed and specified for operation up to 18 GHz, although some versions have a top frequency of 12.4 GHz and some versions are specified at 24 or 26.5 GHz. higher frequency ceilings may require operation at higher return losses Higher frequency ceilings may require operation at higher return losses.

Typically, SMA RF Termination has a higher reflection coefficient than other connectors up to 24 GHz. This is due to the difficulty of fixing the dielectric support precisely, but despite this difficulty, some manufacturers have managed to overcome this problem properly and are able to specify their connectors for operation at 26.5 GHz.

With flexible cables, the frequency limit is usually determined by the cable rather than the connector. This is because the cables accepted by SMA connectors are small, and their losses are naturally much greater than those of the connectors, especially at the frequencies they may be used.

Third, the SMA RF Termination power rating

In some cases, the SMA RF Termination power rating may be important. The key parameter that determines the average power handling capability of the mating coaxial connector is its ability to deliver high current and maintain thermal rise to a moderate temperature.

The heating effect is primarily caused by contact resistance, which is a function of the contact surface area and the way the contact pads come together. A critical area is the center contacts, and these must be properly formed and fit together well. It should also be noted that the average power rating decreases with frequency, as resistance losses increase with frequency.


Suppliers of SMA RF Termination from china


SMA RF Termination's power handling figures vary widely between manufacturers, but some figures indicate that some can handle 500 watts at 1 GHz, dropping to slightly less than 200 watts at 10 GHz, although this is also measured data and may actually be somewhat higher.