External attenuation reduces power before the analyzer connector. Internal attenuation adjusts the instrument's signal path and may not protect every component ahead of it.
How it works in practice
Read the analyzer's maximum RF and DC input specifications independently of its internal attenuation setting. An external pad must safely handle the source and reduce the connector input to an allowed level. The internal setting can then help manage mixer level and dynamic range according to the instrument manual.
Example and interpretation
A 40 dBm source and an ideal 30 dB external pad produce about 10 dBm at the analyzer connector, before considering tolerance and transients.
Checks before use
- Read connector input limits
- Calculate worst-case external reduction
- Check the external pad's rating
- Set internal attenuation using the manual
Important limit
Do not treat a high internal attenuation setting as unlimited input protection.
Related Centron RF product
SMA 5 W 6 GHz fixed attenuator. The SMA 5 W model is listed as a 50-ohm fixed attenuator with a DC–6 GHz range. Select an available attenuation option and verify the current tolerance, cooling conditions and pulse limits for your application.
Further reading
Keysight: Spectrum Analysis Basics. This background reference explains general principles; the selected Centron RF model’s datasheet governs its own ratings.
Related guides
- RF Attenuator Power Rating Versus Dissipated Power
- Selecting Attenuation for a Sensitive RF Receiver
Educational guide. Numerical examples use the stated assumptions and are not test results for a supplied unit.