20-30GHz Low Noise Amplifier

CHA2193

Ref. : DSCHA21939042-11 Feb 99

7/10

Specifications subject to change without notice

Route Départementale 128 , B.P.46 - 91401 ORSAY Cedex - FRANCE

Tel.: +33 (0)1 69 33 03 08 - Fax : +33 (0)1 69 33 03 09

-10

-8

-6

-4

-2

0

2

4

6

8

10

12

14

16

18

20

-28

-26

-24

-22

-20

-18

-16

-14

-12

-10

-8

-6

Input power (dBm)

Gain

(dB)

Pout

(dBm)

Typical Bias Tuning for Low Noise Operation

For low noise operation, a separate access to the gate voltages of the first stage ( Vgs1 ), and of the

second and third stages ( Vgs2 ) is provided.

Nominal bias for low noise operation is obtained for a typical current of 20 mA for the second and third

stages and 10 mA for the first stage ( 50 mA for the amplifier ).

The first step to bias the amplifier is to tune the Vgs1 = -1V, and Vgs2 to drive 40 mA for the full

amplifier. Then Vgs1 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 bias voltage, but keeping the

previous value for Vgs2.