NXP Semiconductors BGA7210, User Manual

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UM10480 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
User manual Rev. 2 — 26 July 2011 8 of 13
NXP Semiconductors
UM10480
Variable gain amplifier BGA7210
6.3 Output third-order intercept point
The output intercept point (OIP3) is a figure of merit for linearity; see Figure 5 . The set-up
is configured to achieve an accurate measurement of the OIP3; see Figure 6 . After the
signal generators, a Low-Pass Filter (LPF) and isolator is applied, before combining the
two signals. This configuration gives best isolation between the generators, hence IMD3
levels of the input signal <

80 dBc can be measured.
Please refer to the BGA7210 data sheet for power level and tone spacing values.
Fig 5. Definition of output intercept point (OIP3)
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2*f
1
-f
2
f
1
f
2
f 2*f
2
-f
1
IMD3
output
power
dBc
dBc
fundamental
slope 1:1
saturation
region
IMD3
slope 1:3
IP3
input power
Fig 6. Output intercept point (OIP3) set-up
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POWER
SUPPLY
MMIC
DUT
SIGNAL
GENERATOR
SIGNAL
GENERATOR
ISOLATOR
LOW-PASS
FILTER (LPF)
POWER
COMBINER
SPECTRUM
ANALYZER
ISOLATOR
LOW-PASS
FILTER (LPF)