[ath9k-devel] TX power and TPC

[Benoit Papillault <benoit.papillault@free.fr>]

Le 12/06/2012 11:28, Holger Schurig a ?crit :
> To your question 2: are both the spectrum analyzer and the USB power
> sensor calibrated?

The spectrum analyzer was bought with calibration certifications.
The USB power sensor has been Zero Calibrated once before all measures.

> Also, do all components have matching impedance?

Sure. 50 Ohms here.

>
> Also, do they all use short coax cable that don't eat up much of the
> power?  Do you know the cable type?  If a cheap cable is used, then
> even a short piece of cable or a cheap plug can reduce the signal
> considerable at 5 GHz. For example, RG 58 CU (which no one uses for
> GHz things) has 100 dB loss for 100 meters at 2 GHz. Aircell 5  has
> 81.18 dB loss at 100 meter at 5 GHz. And so on.
>

The same cable (2m, LMR-200 I guess) was used for both type of measures. 
No attenuators was used (the SA has some internal attenuators and the 
power sensor range is up to +20 dBm).

Regards,
Benoit