NXP Semiconductors AN10714, Примечание к применению

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AN10714_1 © NXP B.V. 2010. All rights reserved.
Application note Rev. 01 — 26 January 2010 12 of 21
NXP Semiconductors
AN10714
Using the BLF574 in the 88 MHz to 108 MHz FM band
Figure 8 compares the performance of Class-B and Class-AB amplifier configurations.
Figure 9 shows the second order harmonic performance.
BLF574 at 98 MHz, I
Dq
= 200 mA.
(1) 46 V.
(2) 48 V.
(3) 50 V.
(4) 52 V.
Fig 7. Output gain and efficiency variation under different drain voltage conditions
BLF574 at 98 MHz, V
DD
= 50 V.
(1) 200 mA.
(2) 1 A.
Fig 8. Output gain and efficiency comparison for Class-B and Class-AB amplifiers
P
L
(W)
0 800 600 400 200
001aal360
24
20
28
32
G
P
(dB)
16
40
20
60
80
η
D
(%)
0
G
P
η
D
(1)
(2)
(3)
(4)
(1)
(2)
(3)
(4)
P
L
(W)
0 800 600 400 200
001aal309
24
20
28
32
G
P
(dB)
16
40
20
60
80
η
D
(%)
0
G
P
η
D
(1)
(2)
(1)
(2)