ôinverted SMAö 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.

 

[biff44]

Jeez, that is a new one on me. Never heard of an inverted SMA. The purpose of ground on the outer conductor (shield) is to prevent leakage of the RF signal.

There are reverse polarity SMA connectors, common on things like wireless lans, where the FCC requires them so the customer can not hook up a 50 dB gain dish to his unit and blast into the next county. Reverse polarity have a pin where the center hole should be and vice/versa. There ARE adapters for that.

http://www.MaguffinMicrowave.com

Maguffin Microwave wireless design consulting

 

[VEBill]

...the outer is the signal and the inner is the ground...

The above quote is just wrong on several levels.

Biff44 gave you what is almost certainly the correct answer (assuming we're guessing your circumstances correctly).

Basically reversed connector center pin/socket gender. As a preventative measure it worked for about a year. Now high gain wifi antennas are readily available, as well as the industry-standard "non-standard" (LOL) connector.

 

[Higgler]

I think you're talking about "reverse SMA", which might get the name inverted. I once made that mistake.
A reverse SMA has two configurations;
female outer thread with a center pin contact
male outer thread/ring with a female inner contact.

I'm not sure that prompted that design. I'm sure it's needed. People don't invent new stuff for no reason.

Hence, there is no reversing of polarity in the connector. Just semantics in a new sma configuration.

 

[VEBill]

It was (is?) an FCC rule to "prevent" (sic) consumers upgrading the antenna on their unlicensed WiFi equipment.