RHF330 STMICROELECTRONICS [STMicroelectronics], RHF330 Datasheet - Page 16

• Manufacturer Part Number: RHF330
• Description: Rad-hard 1 GHz low noise operational amplifier
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Intermodulation distortion product
6
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Intermodulation distortion product
The non-ideal output of the amplifier can be described by the following series of equations.
Where the input is V
the amplitude of the harmonics of the output signal V
A one-frequency (one-tone) input signal contributes to harmonic distortion. A two-tone input
signal contributes to harmonic distortion and to the intermodulation product.
The study of the intermodulation and distortion for a two-tone input signal is the first step in
characterizing the driving capability of multi-tone input signals.
In this case:
Then:
From this expression, we can extract the distortion terms and the intermodulation terms
from a single sine wave.
●
●
The intermodulation product of the driver is measured by using the driver as a mixer in a
summing amplifier configuration
problem of an external mixing device is avoided.
Second order intermodulation terms IM2 by the frequencies (
amplitude of C2A
Third order intermodulation terms IM3 by the frequencies (2
and (
V
out
=
1
C
0
2
+
) with an amplitude of (3/4)C3A
C
1
in
A
=Asin t, C
sin
2
.
1
t
V
+
out
A
Doc ID 15576 Rev 3
sin
0
=
(Figure 31 on page
is the DC component, C
C
V
2
0
t
in
+
+
C
=
C
1
A
V
2
sin
in
A
+
sin
C
1
3
t
2
.
+
1
V
t
2
A
+
in
sin
A
17). In this way, the non-linearity
out
+
sin
.
2
+
t
1
2
C
(V
t
n
2
in
V
) is the fundamental and C
n
in
+
C
1
n
-
1
A
-
2
sin
), (2
2
) and (
1
t
1 2
+
A
1 2
), (
sin
) with an
2
1
RHF330
t
+2
n
2
n
)
is