RF5111_15 Datasheet, PDF (12/14 Pages) RF Micro Devices – DCS POWER AMPLIFIER

RF5111
Typical Test Setup
Power Supply
V- S- S+ V+
RF Generator
3dB
DESIGNS ^10dB/5W
Spectrum
Analyzer
Pulse
Generator
Buffer
x1 OpAmp
NEW
Notes about testing the RF5111
A buffer amplifier is recommended because the current into the
V_APC changes with voltage. As an alternative, the voltage may be
FOR^{monitored with an oscilloscope.}
The test setup shown above includes two attenuators. The 3dB pad at the input is to minimize the effects that the switching of
the input impedance of the PA has on the signal generator. When V_APC is switched quickly, the resulting input impedance
T _{change can cause the signal generator to vary its output signal, either in output level or in frequency. Instead of an attenuator}
an isolator may also be used. The attenuator at the output is to prevent damage to the spectrum analyzer, and should be able
NO ^{to handle the power.}
It is important not to exceed the rated supply current and output power. When testing the device at higher than nominal supply
voltage, the V_APC should be adjusted to avoid the output power exceeding +36dBm. During load-pull testing at the output it is
important to monitor the forward power through a directional coupler. The forward power should not exceed +36dBm, and
V_APC needs to be adjusted accordingly. This simulates the behavior for the power control loop in this respect. To avoid damage,
it is recommended to set the power supply to limiting the current during the burst, not to exceed the maximum current rating.
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Rev A1 DS150909