Sma Cable Insertion Loss

It is a weak function of frequency and cable type.

Sma cable insertion loss.

Insertion loss expressed in db is defined as 10 log po pi where po power out and pi power in. Loss is a length multiplier so a 200 ft length would have twice the loss shown above and a 50 ft length would have half the loss. Cable status codes status code description c custom s stock n non stock connector specifications series impedance frequency range insertion loss sma rp sma 50ω 0 12 4ghz 0 04db max mcx rp mcx 50ω 0 6ghz mmcx 50ω 0 6ghz cable length tolerance cable assembly capabilities connector choices for cable assemblies connector choices for. The shaded region denotes the specified operating frequency range of these cables.

Each cable has a low vswr of 1 4 from dc to 18 ghz as well as a low insertion loss see the table below. Reflected losses are those losses caused by the vswr of the connector. There are 3 main causes of insertion loss. The smp connector can mate directly to a gpo connector while the sma connector can mate directly to a 2 92 mm 3 5 mm or k connector.

A number of years ago i ran into a situation with an installation that had used some radio shack pl 259 and pl 258 connectors in the commercial 450 mhz band in which each connector had an insertion loss of just over 1 db per connector. The graph above shows the insertion loss for sma to sma microwave cables. Shorter cables show a greater effect. Insertion loss change is in percent db relative to 0 db change at 25 c.

Most adapters have a very low loss one that cannot be measured without some pretty good test equipment. To a lesser extent the loss tangent of the eptfe is also a function of temperature. Insertion loss change is primarily due to the change in conductivity of the silver with temperature. Test frequency 6 0 ghz military specifications mil c 39012 mil c 83517 sma.

Ripples in the insertion loss are a function of the cable length and a normal result of reflections between the ends of the cables. Reflected losses dielectric losses and copper losses. Sma coaxial connectors crimp terminations for flexible cable. Right angle panel mount cable jack 2 hole flange sma 4 11 27 01 5 05 pm page 29.

In general we recommend using the shortest cable that is suitable for your application. This measurement was taken at 18 ghz.