 Figure 1) Standard male SMA plug connector: SMA-M with male contact SMA (SubMiniature version A) connectors are coaxial RF connectors developed in the 1960's as a minimal connector interface for coaxial cable with a screw type coupling mechanism. The connector has a 50 Ω impedance. It offers excellent electrical performance from DC to 18 GHz. SMA and precision SMA-like connectors are by far the most popular coaxial connector, though by modern standards, their performance and durability are somewhat limited. Wikipedia does not have an article with this exact name. ...
An RF connector is an electrical connector designed to work at radio frequencies in the multi-megahertz range. ...
Image File history File links SMA_connector. ...
Image File history File links SMA_connector. ...
coaxial cable In geometry, coaxial means that two or more forms share a common axis; it is the three-dimensional analog of concentric. Coaxial cable, for example, has a conducting wire in the center and a second conducting layer running all the way around the exterior circumference, under the insulation. ...
An RF connector is an electrical connector designed to work at radio frequencies in the multi-megahertz range. ...
Events and trends The 1960s was a turbulent decade of change around the world. ...
An electrical connector is a device for joining electrical circuits together. ...
Coaxial Cable Coaxial cable is an electrical cable consisting of a round conducting wire, surrounded by an insulating spacer, surrounded by a cylindrical conducting sheath, usually surrounded by a final insulating layer (jacket). ...
Omega (Ω ω) is the 24th and last letter of the Greek alphabet. ...
Electrical impedance, or simply impedance, is a measure of opposition to a sinusoidal alternating electric current. ...
Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ...
A gigahertz is a billion hertz or a thousand megahertz, a measure of frequency. ...
Connector Design The SMA connector consists of a 0.250x36 thread. The male is equipped with a .312 inch hex nut. It is important that the nut be properly torqued with a 5/16 inch wrench, 3-5 in-lbs for brass, and 7-10 in-lbs for stainless steel connectors. When turning the nut, it is very important that the remainder of the connector does not rotate, otherwise premature wear of the connector will result. Furthermore, the connector should be carefully inspected before each use, and any debris cleaned with compressed air. When properly handled, a SMA connector should remain within specified performance through 500 mating cycles.
The SMA connector uses a PTFE dielectric which will contact along the mating plane. Variablilty in the construction and the mating of the connectors limit the repeatability of the connector impedance. For that reason, a SMA connector is not a good choice for metrology applications.
Variations The SMA connector is typically rated for mode-free operation from DC to 18 GHz, though some propietary versions are rated to 26.5 GHz. For performance above this, SMA-like connectors are used. These are the 3.5 mm connector, rated to 34 GHz, and the 2.92 mm, good up to 46 GHz. These connectors keep the same outside thread as the SMA, so they can all be cross-mated, however they use an air dielectric, with the center conductors appropriately scaled. However, the life of the precision connector will be reduced, and can be easily damaged when mating with low-grade SMA connectors.
Beyond 46 GHz, the 2.4 mm, 1.85 mm and the 1 mm connector exist. These are similar to the SMA connector, but with the geometries incompatibly scaled. These have mode-free operation to 50, 65, and 110 GHz respectively.
 Figure 2) Proprietary female RP-SMA jack connector: RP-SMA-F with male contact Image File history File links Gniazdo_RPSMA.jpg‎ Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): SMA connector ...
Image File history File links Gniazdo_RPSMA.jpg‎ Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): SMA connector ...
Reverse polarity SMA Reverse polarity SMA (RP-SMA or RSMA) is a proprietary variation of the SMA connector specification which reverses the gender of the interface, as shown in Figures 1 and 2. The male RP-SMA connector has the same external housing as a standard male SMA connector; however, the internal prong is replaced by a receptacle. The female RP-SMA connector has the same housing as a standard female SMA connector however the prong found on a male SMA connector is on the female RP-SMA connector.
RP-SMA connectors are widely used by Wi-Fi equipment manufacturers to comply with specific local regulations, e.g. the FCC, which are designed to prevent consumers from connecting antennas with gain and therefore breach compliance. Official Wi-Fi logo Wi-Fi, popularly known as an acronym for wireless fidelity (see below for origin), but, in actuality is simply a play on the term Hi-Fi, was originally a brand licensed by the Wi-Fi Alliance to describe the embedded technology of wireless local area networks...
The FCCs official seal. ...
The term "reverse polarity" might appear confusing to some non-WiFi RF engineers, as polarity elsewhere in RF literature can refer to the electromagnetic polarity, not to a change of gender.
References - Radio-frequency connectors. Part 15: R.F. coaxial connectors with inner diameter of outer conductor 4.13 mm (0.163 in) with screw coupling — Characteristic impedance 50 ohms (Type SMA). International Standard IEC 60169-15, 1979.
- CECC 22110/111
- Connectors, plug, electrical, radio frequency. Military specification sheet MIL-C-39012.
The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ...
External Links
See also |
Feeds |
Contact