Promax MO-180 Manual De Usuario página 101

USER'S MANUAL MO-180
The n-th quantised power abscissa can be obtained from the relative input
power P in dB as follows:
n
Power
⎣ ⎦
⋅
where represents the integer part of its argument. The valid range for the power
abscissae goes from 147 to 36928. When loading these powers into the modulator, it
must be ensured that they are sorted in increasing order, that is, P
all n, and that all used abscissae are stored in consecutive indices. In the case of all
abscissae being 0, the NLPD block is automatically bypassed.
Continuing with the example of figure 3, we show on top of the red correction
curve 16 power abscissae P
not have to be equally spaced. In fact, since the NLPD algorithm relies on linear
interpolation to calculate the correction gain for levels lying in between the reference
points, a better strategy is to use as many points as possible in areas where the
behaviour of the amplifier more markedly departs from linearity. For input powers less
than min(P ), the NLPD block applies the correcting gain corresponding to the point
n
with minimum P . For levels greater than max(P
n
associated to the reference point with maximum P
To each input power P
The NLPD block has a correction range of —6 dB to +6 dB with a resolution of
0.1 dB for the gain amplitude G
resolution of 0.1° for the gain phase θ
(dB) and φ
Given G
n
modulator are computed using:
Gain real
Similarly, the integer gain imaginary ordinates are:
Gain imag. ordinate
04/2008
⎢ ⎥
P
n
⎢ ⎥
= ×
abscissa (n) 2330 10 10
⎢ ⎥
⎣ ⎦
ranging from —12 dB to +12 dB in 1.6 dB steps. Points do
n
corresponds a complex correction gain:
n
⎛
=
⎜
g g exp
n n
⎝
= 20 log
n 10
.
n
(°), the non-negative gain real ordinates to load into the
n
⎢
G
n
⎛ φ
⎢
15 n
= π
ordinate (n) 20 ⎜
2 10 cos
⎢
180
⎝
⎣
⎧
⎢
G
n
⎛ φ
⎪
⎢
15
20 ⎜
2 10 sin
⎪
⎢
⎝ 180
⎪
⎣
=
(n)
⎨
⎢
G
⎪ n
⎢
16 15
+
20
⎪ 2 2 10 sin
⎢
⎪
⎣
⎩
(1)
), the NLPD block uses the gain
n
.
n
φ
⎞
π
⎟
j n
180 ⎠
|g |, and a range of —30° to +30° with a
n
⎥
⎞
⎥
⎟
⎥
⎠
⎦
⎥
⎞
⎥
n
π ⎟ ≤ φ ≤
º 0 30 º
n
⎥
⎠
⎦
⎥
φ
⎛ ⎞
⎥
n
⎜ π ⎟ − ≤ φ <
30 º º 0
n
⎥
180
⎝ ⎠
⎦
< P + 0.1 dB for
n n+1
(2)
(3)
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