It says in "GSM and EDGE Guide, Agilent Technologies PSA Series" that:
Ext RF Atten- Allows you to access the following menu to enter the
external attenuation values...
MS- Allows you to set an externalattenuation value for MS tests
The range is −50.00 to +50.00 dB with 0.01 dB resolution.
BTS- Allows you to set an external attenuation value for BTS
tests. The range is −50.00 to +50.00 dB with 0.01 dB resolution.
However, I have been setting BTS external attenuation to 56.3dB (the offset of my setup) all along, without noticing any warning or error, and the absolute power levels actually doesnt seem to clip at 50dB offset. But I do wonder whether there's any unseen erros happening here.
Also isnt' this merely an offset to the measurement results? Why limit it to a -50dB to +50dB range?
Ext RF Atten- Allows you to access the following menu to enter the
external attenuation values...
MS- Allows you to set an externalattenuation value for MS tests
The range is −50.00 to +50.00 dB with 0.01 dB resolution.
BTS- Allows you to set an external attenuation value for BTS
tests. The range is −50.00 to +50.00 dB with 0.01 dB resolution.
However, I have been setting BTS external attenuation to 56.3dB (the offset of my setup) all along, without noticing any warning or error, and the absolute power levels actually doesnt seem to clip at 50dB offset. But I do wonder whether there's any unseen erros happening here.
Also isnt' this merely an offset to the measurement results? Why limit it to a -50dB to +50dB range?
The GSM application for PSA was leveraged for the E4406A, and it was the first application on E4406A back in 1998. The limit was set arbitrarily. Other applications since then have increased the limit to 100 dB. Also, we have since gotten better about putting an error in the error queue whenever a limit is clipped to its upper or lower range. Nevertheless, the PSA is a mature product, and has been shipping for over 11 years. Current development resources are focused on X-Series Signal Analyzers. I can understand that you may want to put 56.3 dB of external attenuation between a base station that puts out +46 dBm of power and the PSA. As a work around, you could instead enter 46.3 dB of attenuation and understand that the absolute power results are 10 dB off when reported by the analyzer.
Regards -