Connector
Power Handling
How much power can your coaxial connector handle? This reference shows average CW power ratings for 9 standard connector types from 1 GHz to 110 GHz. Use the selector to find which connectors meet your power and frequency requirements.
Connector Selection Guide
Enter your operating power and frequency. The tool instantly shows which connectors can handle your requirements and which fall short.
Power Handling vs. Frequency
Log-log chart showing average CW power handling for all 9 standard coaxial connector types. Power decreases with frequency due to the skin effect. Hover over the chart for exact readings.
Connector Power Handling Table
Average CW power handling in watts at key frequency points. All values assume sea-level atmospheric pressure, 25°C ambient temperature, and matched 50Ω load. Apply a minimum 2x safety derating factor for continuous operation.
| Connector Type |
Impedance (Ω) |
Max Freq (GHz) |
Interface Coupling |
1 GHz (W) |
5 GHz (W) |
10 GHz (W) |
18 GHz (W) |
26 GHz (W) |
40 GHz (W) |
67 GHz (W) |
110 GHz (W) |
|---|
• All power ratings are average CW (continuous wave) at sea level and 25°C
• Peak power ratings are typically 10-30x higher depending on pulse width and duty cycle
• Derate by 2x minimum for continuous operation and thermal margin
• Altitude derating: reduce power handling by ~30% at 10,000 ft and ~50% at 30,000 ft
• "--" indicates the connector does not operate at that frequency
• Values derived from connector manufacturer specifications and MIL-STD data
Connector Interface Details
Physical characteristics and compatibility for each connector type. Larger center conductors handle more power but limit maximum frequency.
| Connector | Center Pin Diameter |
Outer Dia (Interface) |
Dielectric | Coupling | Freq Range | Compatible With |
|---|---|---|---|---|---|---|
| Type N | .120" | .312" | Air | Threaded | DC - 18 GHz | N only |
| TNC | .042" | .188" | PTFE | Threaded | DC - 18 GHz | TNC only |
| SMA | .050" | .188" | PTFE | Threaded | DC - 27 GHz | 3.5mm (with care) |
| SSMA | .032" | .120" | PTFE | Threaded | DC - 36 GHz | SSMA only |
| 3.5mm | .050" | .161" | Air | Threaded | DC - 33 GHz | SMA, 2.92mm |
| 2.92mm (K) | .046" | .134" | Air | Threaded | DC - 40 GHz | SMA, 3.5mm |
| 2.40mm | .040" | .110" | Air | Threaded | DC - 50 GHz | 1.85mm |
| 1.85mm (V) | .032" | .085" | Air | Threaded | DC - 67 GHz | 2.40mm |
| 1.00mm | .017" | .046" | Air | Threaded | DC - 110 GHz | 1.00mm only |
Why Power Handling Drops with Frequency
The average power handling of a coaxial connector is limited by internal heating from resistive (I²R) losses. At higher frequencies, the skin effect forces current to flow in an increasingly thin layer on the conductor surface, which increases effective resistance and generates more heat per unit of transmitted power.
The Skin Effect
At DC, current flows through the entire cross-section of a conductor. At RF frequencies, current concentrates near the surface. The depth at which the current density drops to 37% of the surface value is called the skin depth (δ):
Where: f = frequency (Hz), μ = permeability, σ = conductivity
Because skin depth is proportional to 1/√f, the effective resistance of the conductors increases as √f. This means power handling decreases approximately as 1/√f, which produces the characteristic straight-line curves on a log-log chart (shown above).
Average vs. Peak Power
- Average power is limited by thermal effects. The connector must dissipate heat without exceeding its temperature rating (typically 165°C for PTFE-filled connectors, higher for air-dielectric types). The chart on this page shows average CW ratings.
- Peak power is limited by voltage breakdown. The peak voltage across the air gap between the center and outer conductors must not exceed the breakdown voltage of the dielectric (air or PTFE). Peak power ratings are typically 10-30x higher than average CW, depending on pulse width, duty cycle, and altitude.
Altitude Derating
At higher altitudes, reduced air pressure lowers the voltage breakdown threshold. For connectors operating at high altitude or in unpressurized aircraft, apply these approximate derating factors:
- Sea level: Full rated power (1.0x)
- 5,000 ft (1,524 m): 0.85x
- 10,000 ft (3,048 m): 0.70x
- 20,000 ft (6,096 m): 0.55x
- 30,000 ft (9,144 m): 0.45x
- Vacuum: Approximately 0.10x (use pressurized connectors or waveguide)
When to Use Waveguide Instead
Above approximately 500 watts average at any frequency, or above 50 watts at millimeter-wave frequencies, waveguide becomes the preferred transmission medium. Waveguide handles significantly more power than coaxial connectors because the electromagnetic fields do not require a center conductor, eliminating the primary heat source. For high-power radar, satellite uplinks, and broadcast transmitters, waveguide flanges replace coaxial connectors in the high-power stages.
Frequently Asked Questions
How much power can an SMA connector handle?
An SMA connector handles approximately 500 watts at 1 GHz, dropping to about 100 watts at 18 GHz. At its upper frequency limit of 27 GHz, power handling is approximately 60 watts. These ratings assume sea-level pressure, 25°C ambient, and a matched load. Always apply a 2x safety factor for continuous operation.
What is the maximum power for a Type N connector?
Type N is the highest-power standard coaxial connector, handling approximately 1,600 watts at 1 GHz and 300 watts at 11 GHz. Its large center conductor and air dielectric give it the best thermal performance. Type N is preferred for base station feeds, test systems, and any application requiring high power below 18 GHz.
Why does connector power handling decrease with frequency?
The skin effect concentrates current in an increasingly thin layer on the conductor surface as frequency increases. This raises the effective conductor resistance and generates more heat per watt of transmitted power. The relationship is approximately P ∝ 1/√f, producing straight-line curves on logarithmic scales.
Can I mate SMA with 3.5mm or 2.92mm connectors?
In most cases, yes. SMA, 3.5mm, and 2.92mm (K) connectors share the same outer coupling thread. However, SMA uses a PTFE-loaded interface while 3.5mm and 2.92mm use air dielectric with a different center contact geometry. Mating SMA with 3.5mm is generally acceptable below 18 GHz. Above that, use only precision-grade adapters and verify the center pin engagement.
What is the difference between average and peak power handling?
Average power is limited by heating (thermal). Peak power is limited by voltage breakdown (arcing). For pulsed systems, the average power determines if the connector will overheat, while peak power determines if it will arc. A radar with 10 kW peak and 1% duty cycle has 100W average, so the connector must handle both 100W average and 10 kW peak at the operating frequency.