What is the relationship between power handling and frequency for a coaxial connector?
Frequency-Dependent Connector Power
At higher frequencies, the skin depth decreases, forcing current to flow in a thinner layer near the conductor surface. This increases the effective resistance at the connector contact interface, generating more heat per watt of transmitted power. The connector body and center pin act as short sections of transmission line with loss that increases with frequency.
| Parameter | Class A | Class AB | Class F/Doherty |
|---|---|---|---|
| Max Efficiency | 50% | 50-78% | 70-90% |
| Linearity | Excellent | Good | Moderate (needs DPD) |
| P1dB Backoff | 0-3 dB | 3-6 dB | 6-10 dB |
| Complexity | Low | Low | High |
| Common Use | Test, small signal | General PA | Base station, broadcast |
Frequently Asked Questions
Does the cable affect connector power handling?
Yes. The cable's power rating may be lower than the connector's. The system power limit is the lower of the cable and connector ratings. Flexible cables typically have lower power ratings than semi-rigid cables of the same diameter because the inner conductor is stranded rather than solid.
Can I use an adapter between connectors?
Adapters add additional connector interfaces, each with its own loss and temperature rise. The adapter's power rating may be lower than either connector it connects. Minimize the use of adapters in high-power signal paths.
How do I verify in my application?
Measure the connector temperature during operation using a thermocouple or infrared camera. If the outer conductor temperature exceeds 80-100°C, the connector is approaching its thermal limit. Allow 20°C margin below the maximum operating temperature.