CHA2394_15 Datasheet, PDF (6/8 Pages) United Monolithic Semiconductors – 36-40GHz Very Low Noise High Gain Amplifier

CHA2394
36-40GHz Very Low Noise Amplifier
Typical Bias Tuning for Low Noise Operation
The circuit schematic is given below:
Vd
100
100
50
IN
OUT
Vg 1,2
Vg 3
For low noise operation, a separate access to the gate voltages of the two first stages (Vgs1&2), and of
the output stage (Vgs3) is provided.
Nominal bias for low noise operation is obtained for a typical current of 20 mA for the output stage and
15 mA for each of the two first stages (50 mA for the amplifier).
The first step to bias the amplifier is to tune the Vgs1&2 = -1V, and Vgs3 to drive 20 mA for the full
amplifier.
Then Vgs1&2 is reduced to obtain 50 mA of current through the amplifier.
A fine tuning of the noise figure may be obtained by modifying the Vgs1&2 bias voltage, but keeping
the previous value for Vgs3.
Ref. : DSCHA23946354 - 20 Dec 06
6/8
Specifications subject to change without notice
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