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Connector confusion!
- Thread starter Cloudsuck
- Start date
Yeah, you got to love that one.
Hi Cloudsuck,
Your rule can lead to trouble.
SMA connectors (coaxial) have been in use for years. Look at the center contact: If it sticks out the connector is male and if the center is convex or a sleeve the connector is female. The RP-SMA connectors are intended to NOT be compatible with the SMA series of connectors. Be careful, polarity in connectors refers to male or female (center contacts). You mention "RHCP" above. RHCP or right hand circular polarization (RHCP) refers to the orientation of the radiated signal from an antenna. "Polarity "is also used to describe the orientation of the radiation, hence more confusion. Polarity of the connector and polarity of the radiation are different issues. The photograph also mentions this distinction but is inconsistent with the contact sex.
There is more confusion introduced by the photograph. The generally accepted rule for coax connectors is that the sex of the connector is determined by the center conductor contact. If it sticks out, male. If the contact is a sleeve, female. Some references look at the outer contact for the sex leading to a fight about male vs female. The photograph leads to that debate.
An antenna with different polarity (male/female or SMA/ RP-SMA) can all produce RHCP radiation. Konrd mentions that both the electrical and housings are reversed. Both the SMA and RP-SMA have the same housing. This housing is also the outer conductor of the coax. Only the inner contact pair is reversed with the idea that now that the SMA and RP-SMA are no longer compatible. Both electrical and housings are not reversed. Remember that a coaxial conductor is basically a hollow tube conductor surrounding a center wire conductor. Two conductors are in play.
When examining a coaxial connector pay attention to the "sex (M/F)" of the center connector as well as how the outside contact is threaded. Other common connectors include TNC, BNC, and various others used for microwave frequencies. Most common in modeling applications are the Hirose miniature (U.FL) and RP-SMA versions. From a performance view RP-SMA connectors are far superior to the U.FL series of coaxial connectors.
In the photograph above one can see that male and female SMA's will connect as well as RP-SMA male and female(remember the discussion about male/female convention above). As I pointed out SMA and RP-SMA will not mate correctly. Be careful if you have a mix of RP-SMA's and SMA's. They will either mate and destroy each other or mate without the center contacts touching (minimal signal gets through).
Just remember that polarity in connectors is a separate issue from polarity in radiation. M/F refers to connectors. RHCP refers to radiation. Coax connectors can be male, female, and "sexless". There are four primary polarizations, RHCP, LHCP, Vertical, Horizontal, and continuous variations for elliptical polarizations.
Cloudsuck, your comment about sticking to RHCP and M/F center pins and you are good CAN STILL GET YOU incompatible connectors . A coaxial connector can be either male or female. To correctly mate a SMA pair, one is to be male and the other is to be female. The situation is the same for RP-SMA, one side is male and the other is female. Both the shields and center contacts must be compatible. Pin and socket are reversed between SMA and RP-SMA but the outer contact is not.
If you really want to get into a mess take a look at APC-7 coaxial connectors. You will never see one of those in a model (Konrad will probably say it could happen) but it might add understanding to the situation.
If you want to discuss this further feel free to PM me and I will try for more clarity.
Your rule can lead to trouble.
SMA connectors (coaxial) have been in use for years. Look at the center contact: If it sticks out the connector is male and if the center is convex or a sleeve the connector is female. The RP-SMA connectors are intended to NOT be compatible with the SMA series of connectors. Be careful, polarity in connectors refers to male or female (center contacts). You mention "RHCP" above. RHCP or right hand circular polarization (RHCP) refers to the orientation of the radiated signal from an antenna. "Polarity "is also used to describe the orientation of the radiation, hence more confusion. Polarity of the connector and polarity of the radiation are different issues. The photograph also mentions this distinction but is inconsistent with the contact sex.
There is more confusion introduced by the photograph. The generally accepted rule for coax connectors is that the sex of the connector is determined by the center conductor contact. If it sticks out, male. If the contact is a sleeve, female. Some references look at the outer contact for the sex leading to a fight about male vs female. The photograph leads to that debate.
An antenna with different polarity (male/female or SMA/ RP-SMA) can all produce RHCP radiation. Konrd mentions that both the electrical and housings are reversed. Both the SMA and RP-SMA have the same housing. This housing is also the outer conductor of the coax. Only the inner contact pair is reversed with the idea that now that the SMA and RP-SMA are no longer compatible. Both electrical and housings are not reversed. Remember that a coaxial conductor is basically a hollow tube conductor surrounding a center wire conductor. Two conductors are in play.
When examining a coaxial connector pay attention to the "sex (M/F)" of the center connector as well as how the outside contact is threaded. Other common connectors include TNC, BNC, and various others used for microwave frequencies. Most common in modeling applications are the Hirose miniature (U.FL) and RP-SMA versions. From a performance view RP-SMA connectors are far superior to the U.FL series of coaxial connectors.
In the photograph above one can see that male and female SMA's will connect as well as RP-SMA male and female(remember the discussion about male/female convention above). As I pointed out SMA and RP-SMA will not mate correctly. Be careful if you have a mix of RP-SMA's and SMA's. They will either mate and destroy each other or mate without the center contacts touching (minimal signal gets through).
Just remember that polarity in connectors is a separate issue from polarity in radiation. M/F refers to connectors. RHCP refers to radiation. Coax connectors can be male, female, and "sexless". There are four primary polarizations, RHCP, LHCP, Vertical, Horizontal, and continuous variations for elliptical polarizations.
Cloudsuck, your comment about sticking to RHCP and M/F center pins and you are good CAN STILL GET YOU incompatible connectors . A coaxial connector can be either male or female. To correctly mate a SMA pair, one is to be male and the other is to be female. The situation is the same for RP-SMA, one side is male and the other is female. Both the shields and center contacts must be compatible. Pin and socket are reversed between SMA and RP-SMA but the outer contact is not.
If you really want to get into a mess take a look at APC-7 coaxial connectors. You will never see one of those in a model (Konrad will probably say it could happen) but it might add understanding to the situation.
If you want to discuss this further feel free to PM me and I will try for more clarity.
Microwaves 101 has a series of pages on the subject. Lot's of detail.
Microwave Connectors - Microwave Encyclopedia - Microwaves101.com
Microwave Connectors - Microwave Encyclopedia - Microwaves101.com
web.archive.org
