Datasheet

MAX2016
LF-to-2.5GHz Dual Logarithmic Detector/
Controller for Power, Gain, and VSWR Measurements
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Measuring Gain
The MAX2016 can be used to measure the gain of an
RF block (or combination of blocks) through the imple-
mentation outlined in Figure 3. As shown, a coupled
signal from the input of the block is fed into RFINA,
while the coupled output is connected to RFINB. The
DC output voltage at OUTD is proportional to the power
difference (i.e., gain).
The gain of a complete receiver or transmitter lineup
can likewise be measured since the MAX2016 accepts
RF signals that range from low frequency to 2.5GHz;
see Figure 4. The MAX2016 accurately measures the
gain, regardless of the different frequencies present
within superheterodyne architectures.
For accurate measurement of signals carrying signifi-
cant amplitude modulation, limit the bandwidth of the
difference amplifier to be less than the lowest modula-
tion frequency. This will minimize the ripple in the
OUTD waveform. This is particularly appropriate if the
system-level time delay between the two sense points
is significant with respect to the period of modulation.
MAX2016
RFINA
RFINB
IN
LOGARITHMIC
DETECTOR
LOGARITHMIC
DETECTOR
GND
OUTD
SETD
20k
Ω
COUPLER
COUPLER
RF BLOCK
OUT
OUTD
Figure 3. Gain Measurement Configuration
MAX2016
LNA
f
RF
f
IF
RFINA
RFINB
LOGARITHMIC
DETECTOR
LOGARITHMIC
DETECTOR
COUPLER
LO
MIXER
COUPLER
OUTD
SETD
20k
Ω
OUT
Figure 4. Conversion Gain Measurement Configuration