TheA/WA/Wunits refer to the current (in Ampère) produced per Watt of light incident on the photodiode. This current-production happens when the diode operates in the so-called photoconductive mode. Since your question wasn't on the inner workings of a photodiode, I won't expand on this, butWikipediacontains some more information if desired.
kaiser window에서 beta1=16.7일 때 k=2.23 이라는데, k 값이 그러면 amplitude 관련 보정에 대한 그 계수가 아닌가?
Where k is a window-related coeffcient, N is the number of time-domain samples used in the DFT calculation, and Fs is the sampling frequency. For the Kaiser window with beta1 = 16.7, k is about 2.23. The RBW shape factor, defned as the frequency ratio between the spectrum amplitude at 60 dB and 3 dB, is about 4:1. On the RSA5100/6100, the spectrum analysis measurement uses Equation 2 to calculate the required number of samples for the DFT based on the input span and RBW settings.
인데 NENBW는 normalized effective noise bandwidth of the window 라..
RBW - Resolution bandwidth
Resolution bandwidth of the estimate, returned as a scalar.
The resolution bandwidth, RBW, is the smallest positive frequency, or frequency interval, that can be resolved. It is equal to NENBW*SampleRate/L, where L is the input length, and NENBW is the normalized effective noise bandwidth of the window.
The data type of RBW matches the data type of the input.