<s>
SMA	O
(	O
SubMiniature	B-Protocol
version	I-Protocol
A	I-Protocol
)	O
connectors	O
are	O
semi-precision	O
coaxial	O
RF	B-Protocol
connectors	I-Protocol
developed	O
in	O
the	O
1960s	O
as	O
a	O
minimal	O
connector	O
interface	B-Protocol
for	O
coaxial	O
cable	O
with	O
a	O
screw-type	O
coupling	O
mechanism	O
.	O
</s>
<s>
The	O
SMA	B-Protocol
connector	I-Protocol
is	O
most	O
commonly	O
used	O
in	O
microwave	O
systems	O
,	O
hand-held	O
radio	O
and	O
mobile	O
telephone	O
antennas	O
and	O
,	O
more	O
recently	O
,	O
with	O
WiFi	O
antenna	O
systems	O
and	O
USB	O
software-defined	B-Architecture
radio	I-Architecture
dongles	O
.	O
</s>
<s>
The	O
interface	B-Protocol
dimensions	O
for	O
SMA	B-Protocol
connectors	I-Protocol
are	O
listed	O
in	O
MIL-STD-348	O
.	O
</s>
<s>
The	O
SMA	B-Protocol
connector	I-Protocol
employs	O
a	O
inch	O
diameter	O
,	O
36-thread-per-inch	O
threaded	O
barrel	O
.	O
</s>
<s>
There	O
are	O
also	O
reverse-polarity	O
(	O
"	O
RP	O
"	O
)	O
SMA	B-Protocol
connectors	I-Protocol
in	O
which	O
the	O
pin	O
and	O
sleeve	O
are	O
swapped	O
so	O
that	O
the	O
"	O
male	O
"	O
RP-SMA	O
has	O
a	O
center	O
sleeve	O
surrounded	O
by	O
an	O
inside-threaded	O
barrel	O
,	O
and	O
the	O
"	O
female	O
"	O
RP-SMA	O
has	O
a	O
center	O
pin	O
and	O
an	O
outside-threaded	O
barrel	O
.	O
</s>
<s>
The	O
SMA	B-Protocol
connector	I-Protocol
uses	O
a	O
polytetrafluoroethylene	O
(	O
PTFE	O
)	O
dielectric	O
that	O
contacts	O
along	O
the	O
mating	O
plane	O
.	O
</s>
<s>
For	O
that	O
reason	O
and	O
that	O
they	O
are	O
just	O
rated	O
for	O
a	O
limited	O
number	O
of	O
connection	O
cycles	O
,	O
an	O
SMA	B-Protocol
connector	I-Protocol
is	O
not	O
usually	O
a	O
good	O
choice	O
for	O
metrological	O
applications	O
.	O
</s>
<s>
SMA	B-Protocol
connectors	I-Protocol
are	O
rated	O
for	O
up	O
to	O
500	O
mating	O
cycles	O
,	O
but	O
to	O
achieve	O
this	O
it	O
is	O
necessary	O
to	O
properly	O
torque	O
the	O
connector	O
when	O
making	O
the	O
connection	O
.	O
</s>
<s>
SMA	B-Protocol
connectors	I-Protocol
must	O
not	O
be	O
confused	O
with	O
the	O
standard	O
household	O
75-ohm	O
type	B-Protocol
F	I-Protocol
coax	O
connector	O
(	O
diameters	O
:	O
male	O
inch	O
(	O
11mm	O
)	O
circular	O
or	O
hex	O
;	O
female	O
inch	O
(	O
9.5mm	O
)	O
external	O
threads	O
)	O
,	O
as	O
there	O
is	O
only	O
about	O
a	O
2mm	O
difference	O
overall	O
in	O
the	O
specifications	O
.	O
</s>
<s>
Type	B-Protocol
F	I-Protocol
cannot	O
be	O
mated	O
with	O
SMA	B-Protocol
connectors	I-Protocol
without	O
the	O
use	O
of	O
an	O
adapter	O
.	O
</s>
<s>
The	O
SMA	B-Protocol
connector	I-Protocol
is	O
typically	O
rated	O
for	O
mode-free	O
operation	O
from	O
DC	O
to	O
18GHz	O
,	O
though	O
some	O
proprietary	O
versions	O
are	O
rated	O
to	O
26.5GHz	O
.	O
</s>
<s>
These	O
connectors	O
keep	O
the	O
same	O
outside	O
thread	O
as	O
the	O
SMA	O
,	O
so	O
they	O
can	O
potentially	O
be	O
cross-mated	O
,	O
but	O
the	O
precision	O
connector	O
can	O
be	O
easily	O
damaged	O
when	O
mating	O
with	O
low-grade	O
SMA	B-Protocol
connectors	I-Protocol
.	O
</s>
<s>
These	O
are	O
similar	O
to	O
the	O
SMA	B-Protocol
connector	I-Protocol
,	O
but	O
with	O
the	O
geometries	O
incompatibly	O
scaled	O
,	O
and	O
a	O
metric	O
thread	O
to	O
prevent	O
accidental	O
intermating	O
.	O
</s>
<s>
Reverse-polarity	O
SMA	O
(	O
RP-SMA	O
or	O
RSMA	O
)	O
is	O
a	O
variation	O
of	O
the	O
SMA	B-Protocol
connector	I-Protocol
specification	O
that	O
reverses	O
the	O
gender	O
of	O
the	O
interface	B-Protocol
,	O
as	O
shown	O
in	O
Figures	O
1	O
and	O
2	O
.	O
</s>
<s>
The	O
female	O
RP-SMA	O
connector	O
has	O
the	O
same	O
external	O
housing	O
as	O
a	O
standard	O
or	O
conventional	O
female	O
SMA	B-Protocol
connector	I-Protocol
,	O
which	O
consists	O
of	O
an	O
outer	O
shell	O
with	O
the	O
threads	O
on	O
the	O
outside	O
;	O
however	O
,	O
the	O
center	O
receptacle	O
is	O
replaced	O
by	O
a	O
male	O
pin	O
.	O
</s>
<s>
Normal	O
SMA	B-Protocol
connectors	I-Protocol
are	O
incompatible	O
with	O
RP-SMA	O
connectors	O
.	O
</s>
