Power rating of SMA connections?

Gents,

Here is the promised feedback. Got an answer from Tyco this morning. Peak power was stated as 20kW at sea level. Yes, that's kilowatts, had to look twice. Voltage breakdown is given as the limiting factor and peak power must be derated by a factor of 20 for "critical altitude" around 70,000ft.

Another document they sent states a 3mOhm max test requirement for center and outer contact. Now that's very encouraging.

Joerg wrote:

Take into account that SMA is not made for infinitely many mounting cycles... So whatever the manufacturer specifies for a new product, the contact degrades over the cycles.

Rene

You could reasonably assume that most have more gold plating on them than a CAT 6 cable or connector, and those last through a LOT of connect/disconnect cyclings.

I doubt it would change enough to require more than normal consideration. The per connection dB loss in a given path is likely far greater a worry than how many times a given cable was used or a connector, for that matter to comprise one such connection. The loss would stay pretty flat right up until the failure mode. (isn't that always how it is? :-)

There is a standard for the SMA interconnection. I also often see various sized coaxes (all 50 ohm) between elements which usually correlate directly to how much power is being pushed (or clamped in the case of termination). So the cable characteristics and raw connection count are likely more important than the connector or connection loss-over-number-of-cycles factor.

Nice data sheet. Some better performers out there, many worse.

A cool database would be real values from all these guys in one place.

On a connector, perhaps. But the cables that interlink things would be where the power bottlenecks are.

Did you look at that log amp I sent you the link to?

The center conductor (nib) of an SMA (M) connector only "inserts" about

So there is no big long sleeve of captivation. It essentially is the tangency between the radius of the nose of the nib, and the split center hole, both being gold plated.

All it takes is ONE loose connector. Remember to torque SMAs properly to 7 to 12 inch Lbs.

Some of our sat gear has huge N type connectors and an SMA on the other end, but I don't think they are passing high power over them. They are more for signal or noise injection, etc. for test regimens.

Yes, Rene, but it's no problem here because this is for internal modules. So typically there will be only one mounting process in the lifetime of the unit. But that lifetime can be very long.

Gold will outlast ANYTHING you call a lifetime.

The album Carl Sagan put on the space probe is Gold plated Copper. It will NEVER oxidize, even after a BILLION years.