“inverted SMA” connector

[jk97]

I am currently designing an experiment which will involve working with a piece of equipment that has an “inverted SMA” connector. From what I understand this is an SMA connector in which the outer is the signal and the inner is the ground. I an wondering if this is a standard thing and if so is it possible to buy a cable or adapter to convert between the conventional arrangement and this one? At the moment I'm not sure how that could be achieved without creating a major impedance discontinuity. Any help with this would be much appreciated.

 

[pstuckey]

Are you sure that's not a "Reverse polarity" SMA connector? These have the pin on female connector rather than the male, but the signal still travels on the inner conductor.

 

[jk97]

Are you sure that's not a "Reverse polarity" SMA connector? These have the pin on female connector rather than the male, but the signal still travels on the inner conductor.

I need to look into it more but I think that this could be what I am looking for. Thanks very much!

 

[biff44]

If it really is inverted like you say, you will need to use an RF transformer 1:1 there you can swap the inverted SMA to the non-inverted SMA on the test gear. You would have to be very careful to make sure the unit's chassis ground is isolated from the test equipment's, including removing any earth ground on the unit (if that is feasible under safe operating rules).

I do suspect you instead just need a reverse polarity to normal SMA connector adapter, though.

 

[jk97]

If it really is inverted like you say, you will need to use an RF transformer 1:1 there you can swap the inverted SMA to the non-inverted SMA on the test gear. You would have to be very careful to make sure the unit's chassis ground is isolated from the test equipment's, including removing any earth ground on the unit (if that is feasible under safe operating rules).

I do suspect you instead just need a reverse polarity to normal SMA connector adapter, though.

Thanks for this reply. O.k., I think that I now have a much better idea of the questions which I need to ask, to establish exactly what form of connection is required. Can this kind of transformer be purchased off-the-shelf?

 

[vedagarbhamsandeep]

why dont you send a pic of your connector so that you could sort out your problem faster.

 

[DeboraHarry]

Reverse polarity SMA (R/P SMA) are often used on consumer devices like WiFi systems. Basically to stop people putting things like amplifiers on them. But it does not really work, as R/P SMA connectors are easily available. I don't think I've seen adapters, (but I've never looked for them), but its easy to put a bit of cable with an N, SMA or whatever you want on one end, and an R/P SMA on the other.

Deborah