Key Performance of SMA RF Connectors
|
Characteristic impedance |
50Ω |
Dielectric withstanding voltage |
1000V |
|
Frequency range |
With flexible cable |
0~12.4GHz |
Contact resistance |
Center conductor |
≤0.003Ω |
|
With seml-rigld/flexible cable |
0~18GHz |
Outer conductor |
≤0.002Ω |
|
VSWR |
With flexible cable |
≤1.15+0.02F |
Durablity |
500Cycles |
|
With seml-rigld/flexible cable |
≤1.10+0.02F |
Interface Mating Dimensions of RF Coaxial SMA Connectors
|
Symbol |
MIN (mm) |
MAX (mm) |
Symbol |
MIN (mm) |
MAX (mm) |
Symbol |
MIN (mm) |
MAX (mm) |
|
a |
3.30 |
一 |
h |
0 |
0.25 |
p |
1/4-36UNS-2A |
|
b |
一 |
3.43 |
|
1.27 |
一 |
q |
φ5.28 |
φ5.49 |
|
C |
0.38 |
1.14 |
j |
- |
2.54 |
r |
φ4.597 |
φ4.670 |
|
d |
φ4.340 |
φ4.592 |
k |
5.54 |
一 |
S |
0 |
0.1 |
|
e |
1/4-36UNS-2B |
I |
4.32 |
|
t |
2.92 |
一 |
|
f |
φ6.35 |
φ6.73 |
m |
1.88 |
1.98 |
u |
φ0.90 |
φ0.94 |
|
g |
0 |
0.1 |
n |
0.38 |
1.14 |
W |
0 |
0.76 |
What is an SMA RF Coaxial Connector?
The SMA (SubMiniature version A) RF coaxial connector is a precision connector designed for coaxial cables that operate at frequencies ranging from DC up to 27 GHz, with some variants supporting even higher frequencies. It features a screw-type coupling mechanism that ensures a secure and vibration-resistant connection, minimizing signal reflections and attenuation.
Originally developed in the 1960s, the SMA connector has evolved to become one of the most widely used connectors in microwave communications, aerospace navigation, wireless systems, and RF measurement equipment due to its:
Small size and lightweight design
High mechanical strength and durability
Excellent electrical performance with low insertion loss
Compatibility with a wide range of coaxial cables
Variations of SMA RF Coaxial Connectors
SMA connectors come in multiple configurations to accommodate different system designs and requirements:
Straight Connectors: The most common type, suitable for direct cable-to-device connections.
Right-Angle Connectors: Ideal for space-constrained PCB layouts or equipment designs.
Bulkhead and Panel Mount Connectors: For secure mounting on equipment panels or enclosures.
Reverse Polarity (RP-SMA): A variant designed to comply with regulatory requirements (e.g., FCC) for Wi-Fi equipment, featuring reversed gender contacts to prevent unauthorized antenna connections.
Additionally, SMA connectors are compatible with various cable types, including flexible, semi-rigid, and low-loss coaxial cables such as RG174, RG316, RG178, and RG58.
