AT-32032 Datasheet, PDF (12/14 Pages) AVAGO TECHNOLOGIES LIMITED – Low Current, High Performance NPN Silicon Bipolar Transistor

Performance
The measured gain of the completed amplifier is shown in
Figure 19. The gain varies
from 15.5 to 16.5 dB over the 800 to 900 MHz frequency
range. Noise figure versus frequency is shown in Figure
20. Best performance occurs at 950 MHz providing a 1.1
dB noise figure.
Measured input and output return loss is shown in Figure
21. The input return loss is 7 dB at 900 MHz and can be
improved to 9 dB with a 0.1 dB increase in noise figure by
increasing the amount of capacitance at C2. Additional
capacitance at C2 increases the input return loss even
further with increased noise figure. Output return loss is a
nominal 12 to 15 dB.
Output intercept point, IP₃, was measured at 900 MHz
to be +14.3 dBm. This could be ­ improved in two ways.
The output resistors R5 and R6 could be varied in value.
Increasing the value of R5 and decreasing the value
of R6 will improve IP₃ although circuit stability may be
sacrificed. The second method would be to optimize the
output match for power as opposed to matching for
lowest VSWR.
Using the AT-32032 at Other Frequencies
The demo board and design techniques presented here
can be used to build low noise amplifiers for other fre-
quencies in the VHF through 1.9 GHz frequency range.
17
16
15
14
13
12
11
10
500
600 700 800 900
FREQUENCY (MHz)
1000
Figure 19. Gain vs Frequency.
1.5
1.4
1.3
1.2
1.1
1
500 600 700 800 900 1000
FREQUENCY (MHz)
Figure 20. Noise Figure vs Frequency.
0
-5
-10
-15
-20
500
Input
Output
600 700 800 900
FREQUENCY (MHz)
1000
Figure 21. Input/Output Return Loss.