Published on 10/13/2026
A design review catches a problem: the layout uses SMA connectors on a 28 GHz link. SMA is not specified for 28 GHz, and the test lab will need a different series. A single reference table of connector frequency limits would have caught it on day one.
Short answer: the maximum frequency is set by the connector series, not the cable. SMA is rated to 18 GHz, 3.5 mm to 34 GHz, 2.92 mm to 40 GHz, 2.4 mm to 50 GHz and 1.85 mm to 67 GHz. N type is rated to 11 GHz (18 GHz for precision versions) and BNC to 4 GHz.
The table below gives typical maximum frequencies, with notes on compatibility between series.
On This Page
| Connector | Typical max frequency | Coupling | Notes |
|---|---|---|---|
| UHF (PL-259 / SO-239) | 300 MHz (to 1 GHz in practice) | Threaded | Not constant impedance |
| F type | 1 GHz (to 3 GHz for satellite) | Threaded | 75 ohm TV and satellite |
| BNC (50 ohm) | 4 GHz (some to 11 GHz) | Bayonet | Low frequency instruments |
| SMB | 4 GHz | Snap-on | Compact, low power |
| MCX / MMCX | 6 GHz | Snap-on | Small, board level |
| U.FL / MHF4 | 6 GHz | Snap-on | Few mating cycles |
| QMA | 6 GHz | Quick lock | Quick-lock SMA alternative |
| 4.3-10 | 6 GHz | Threaded / push | Low PIM mobile base station |
| 7/16 DIN | 7.5 GHz | Threaded | High power, low PIM |
| SMC | 10 GHz | Threaded | Small microwave |
| N type | 11 GHz (18 GHz precision) | Threaded | Robust, power |
| TNC | 11 GHz (18 GHz in precision parts) | Threaded | Threaded BNC form |
| SMA | 18 GHz (precision to 26.5 GHz) | Threaded | Most common microwave |
| 7 mm (APC-7) | 18 GHz | Threaded | Sexless lab standard |
| SSMA | 26.5 GHz | Threaded | Smaller than SMA |
| 3.5 mm | 34 GHz | Threaded | SMA compatible mechanically |
| 2.92 mm (K) | 40 GHz | Threaded | SMA and 3.5 mm compatible |
| SMP / SMPM | 40 GHz (SMPM to 65 GHz) | Push-on | Board to board |
| 2.4 mm | 50 GHz | Threaded | 2.4 and 1.85 mate |
| 1.85 mm (V) | 67 GHz | Threaded | Precision mm-wave |
| 1.0 mm | 110 GHz | Threaded | W band and up |
Values are typical rated maximums from common specifications and vary by maker and grade. Always read the datasheet VSWR curve for your exact part.
| Series | Mates mechanically with | Recommended? |
|---|---|---|
| SMA | 3.5 mm, 2.92 mm | Works, but wears the precision part |
| 3.5 mm | SMA, 2.92 mm | Works; use sparingly |
| 2.92 mm | SMA, 3.5 mm | Works; use sparingly |
| 2.4 mm | 1.85 mm | Works; avoid in calibration |
| 1.85 mm | 2.4 mm | Works; avoid in calibration |
| BNC 50 ohm vs 75 ohm | Mechanically similar | Pin sizes differ; risk of damage |
Key idea: Mixing precision series can mate but degrades the more expensive connector over time. Use adapters, not direct cross-mating, in calibration.
Tell us your band
We will recommend the right connector and cable for your top frequency, and sweep the finished assembly for VSWR and insertion loss before shipment.
Talk to an EngineerRule 01
Find your top frequency
Use the highest frequency in your signal, including harmonics you want to measure.
Rule 02
Keep 20 to 30 percent margin
If the band reaches 16 GHz, pick a connector rated 18 GHz or more, not exactly 18.
Rule 03
Check the cable
The cable must also be rated for that frequency. See the RG316 max frequency article.
Rule 04
Check power and mating cycles
Use N or 7/16 DIN for power, and precision series for repeated mating.
Avoid
What is the maximum frequency of an SMA connector?
About 18 GHz for standard SMA, and 26.5 GHz for precision versions.
What is the maximum frequency of an N connector?
About 11 GHz for standard N, and 18 GHz for precision N.
What frequency does BNC support?
About 4 GHz for standard 50 ohm BNC. Some versions reach 11 GHz.
What is the difference between 3.5 mm and 2.92 mm?
3.5 mm is rated to 34 GHz and 2.92 mm (K) to 40 GHz. Both mate with SMA.
Which connector is best for 40 GHz?
2.92 mm (K) connectors, with 2.4 mm or 1.85 mm for higher frequency.
Can I use SMA at 26 GHz?
Only precision SMA parts, and with care. A 3.5 mm connector is the safer choice.
Pick the connector series from the top frequency, keep margin below the limit and check that the cable and the mating connectors are rated as high.
SigmaRF builds assemblies with SMA, 3.5 mm, 2.92 mm, N, TNC and other series in India (Vadodara) and the USA (Cleveland area), VNA-swept before shipment (100 MHz to 40 GHz), with lead times as short as 2 days.
Order a connector assembly
Send the band, cable and connectors.
Standard AssembliesCustom AssembliesTalk to an Engineer