Published on 10/13/2026
A transmitter datasheet says 40 W at 2.4 GHz. The cable is rated for it, the antenna is rated for it, but is the SMA connector between them? Connector power ratings are rarely printed on the part, they fall with frequency, and they are often lower than the cable in the same assembly.
Short answer: an SMA connector handles roughly 150 W CW at 1 GHz and about 60 W at 6 GHz, an N connector about 400 W at 1 GHz, and a 7/16 DIN connector over 1 kW at 1 GHz. Rating falls roughly with the square root of frequency, and derates with temperature, altitude and VSWR.
The tables below give planning values. They are order-of-magnitude figures scaled from typical 1 GHz ratings, not guarantees. Always use the datasheet for the exact part.
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| Connector | 1 GHz | 3 GHz | 6 GHz | 10 GHz | 18 GHz |
|---|---|---|---|---|---|
| SMA | 150 W | 90 W | 60 W | 50 W | 40 W |
| 3.5 mm | 100 W | 60 W | 40 W | 30 W | 24 W |
| 2.92 mm | 90 W | 50 W | 40 W | 28 W | 21 W |
| BNC | 80 W | 50 W | n/a | n/a | n/a |
| TNC | 200 W | 120 W | 80 W | 60 W | n/a |
| N type | 400 W | 230 W | 160 W | 130 W | n/a |
| 7/16 DIN | 2500 W | 1440 W | 1020 W | n/a | n/a |
| 4.3-10 | 1500 W | 870 W | 610 W | n/a | n/a |
| SMB | 50 W | 29 W | n/a | n/a | n/a |
| MMCX | 20 W | 12 W | 8 W | n/a | n/a |
Typical average CW power at 25 C sea level with a matched load. Planning values from a 1 GHz anchor scaled by 1 divided by the square root of frequency. Cells marked n/a are above the connector's practical frequency range.
⚠️ Watch out: These figures are estimates. Different makers, dielectric materials and plating give different results. For design sign-off, use the manufacturer's rating at your frequency.
Heating in the connector comes from conductor loss and dielectric loss. Both rise with frequency, and small connectors have little surface to shed heat. At the same time, the electric field in the dielectric gap increases the risk of breakdown for pulsed signals.
Key idea: Larger connectors handle more power. 7/16 DIN and 4.3-10 handle kilowatts, N handles hundreds of watts, SMA handles tens to hundreds of watts, and snap-on types handle only a few watts.
Right connector for your power level
Send the frequency, average power and VSWR. We will recommend connectors and cable, and sweep the assembly on a VNA before shipment.
Talk to an Engineer| Condition | Typical derating |
|---|---|
| Ambient 85 C instead of 25 C | Reduce power by 40 to 50 percent |
| Altitude 10,000 m | Reduce peak power substantially; heat shedding is worse |
| VSWR 2:1 | Reduce by about 20 to 30 percent |
| Enclosed space without airflow | Reduce by 20 percent or more |
| Poor or loose mating | Hot spot at the contact; derate heavily |
The values above are average (CW). Peak power for short pulses can be much higher, limited by voltage breakdown, not heat. Breakdown depends on pulse width, altitude and dielectric. For pulsed radar or transmitter work, ask for the peak rating at the duty cycle you use.
Avoid
How much power can an SMA connector handle?
Roughly 150 W CW at 1 GHz, falling to about 60 W at 6 GHz. Check the maker datasheet.
How much power can an N connector handle?
Roughly 400 W CW at 1 GHz, and about 130 W at 10 GHz.
What connector for 1 kW?
7/16 DIN or 4.3-10 at low frequency, or a large N type depending on frequency.
Does connector power rating depend on frequency?
Yes. It drops roughly with the square root of frequency.
Is average or peak power more important?
Check both. Average power limits heating and peak power limits voltage breakdown.
Are these numbers guaranteed?
No. They are planning estimates, so check the datasheet.
Connector power ratings fall with frequency and with heat, and connectors are often the limit in an assembly. Choose the connector for the power and frequency, derate for conditions, and confirm with the datasheet.
SigmaRF builds assemblies with SMA, N, TNC and 7/16 DIN connectors in India (Vadodara) and the USA (Cleveland area), VNA-swept before shipment, with lead times as short as 2 days.
Need an assembly for higher power?
Send the frequency and power.
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