The energy of the stress waves is concentrated at the knee frequency of a target environment especially, thereby minimizing the required trials and errors for tuning the knee frequency of the PPSS.
The SRS matching procedure consists of five steps shown in Figure 8: assigning a target pyroshock environment, tuning the knee frequency of the PPSS to that of the target, matching the SRS slopes in the ramp region, scaling the projectile energy, and retuning the knee frequency of the PPSS to satisfy the SRS magnitude condition.
This result is quite consistent with the knee frequency
(fknee) approach given ,
For this reason, the bandwidth is often referred to as the knee frequency. The lower the knee frequency in the frequency-domain, the longer the rise time of the signal in the time-domain.
This pushes the knee frequency of the signal's spectrum to lower frequency, and increases the rise time of the signal.
Alternatively, r can be calculated from software, using up to three approaches including, for instance, minimizing the final differenced data knee frequency, [f.sub.k].
This can be achieved "if the post detection knee frequency [f.sub.k] (i.e.
By comparison, specifying in the DC section cannot be used to predict performance in the main operating region because the knee frequency
([f.sub.knee]) will change from one device to another.
The formula [X.sub.L] = 2[pi]fL provides the expression for inductive reactance, but here f is the knee frequency
which is defined as 0.5/Tr, Tr = rise time.
The frequency at which this becomes significant is approximately given by (7) [F.sub.c] (P1 dB) = 1/(2 [star] [Pi] [star] [R.sub.g] [star] [C.sub.gs]) The knee frequency
is a function of gate resistance and gate periphery.
There could be several user-based choices (knee frequency
, clock frequency, mean of band, etc.) to pick up as a part of the signal's frequency spectrum.
Both strongly change over the frequency, so derive their values on the signal's knee frequency
. The slope of the Dk curve depends on the Df value, a higher Df leads to a bigger change in Dk over frequency.