#### MMIC Amplifier Bias calculation

Nick Kennedy

If the inductor has a core material other than air, such as powdered iron
or ferrite (and it probably does), the DC current through it could saturate
the core material. That would cause the inductor to become non-linear or
have much lower than marked inductance.

If you know the manufacturer and part number of the inductor you might be
able to look up what value of current would cause it to saturate. Otherwise
you could wind your own inductor on a toroid and use published values of
its properties to be sure you're avoiding saturation.

73-

Nick, WA5BDU

On Fri, May 3, 2019 at 8:17 AM Alfredo Mendiola Loyola via Groups.Io
<mendiola_loyola=yahoo.com@groups.io> wrote:

Good Morning,

I'm using this calculator (
https://www.changpuak.ch/electronics/mar_era_bias.php) to get the values
of
the Capacitors, Resistance and Inductor for my Minicircuits MAV-11BSM
amplifier.

The calculator gives me a capacitor value of 68pF and an inductor of 1.6
uH.

What I don't understand is this statement in the calculator:
*******************************************************************
" Make sure the inductance does not saturate at the current of operation "

The calculated current is 60 mA, and the inductance calculated is 1.6uH.
How do I know if the inductor saturates at 60 mA of Current ?

Parameters:
**********
Supply Voltage: 8
Amp Type: MAV-11BSM
Min Freq: 50 Mhz

Output:
*******
R = 41.67 Ohms
L >= 1.592 uH
C >= 0.0637 nf ( 64pF => 68pF) {Usar 0.1uF}
P = 0.15W
I = 60 mA

Alfredo Mendiola Loyola

I'm still designing the schematic before buyinh the components.
RegardsAlfredo Mendiola Loyola

On Friday, May 3, 2019, 9:25:22 AM GMT-5, Ambro IW2FVO <ambrogio.riboli@...> wrote:

hi Alfredo,
is your si570 working well with the sketch ?
Just to know .
regards,
Ambro
iw2fvo

Ambro IW2FVO

hi Alfredo,
is your si570 working well with the sketch ?
Just to know .
regards,
Ambro
iw2fvo

Alfredo Mendiola Loyola

Good Morning,

I'm using this calculator (https://www.changpuak.ch/electronics/mar_era_bias.php) to get the values of
the Capacitors, Resistance and Inductor for my Minicircuits MAV-11BSM amplifier.

The calculator gives me a capacitor value of 68pF and an inductor of 1.6 uH.

What I don't understand is this statement in the calculator:
*******************************************************************
" Make sure the inductance does not saturate at the current of operation "

The calculated current is 60 mA, and the inductance calculated is 1.6uH.
How do I know if the inductor saturates at 60 mA of Current ?

Parameters:
**********
Supply Voltage: 8
Amp Type: MAV-11BSM
Min Freq: 50 Mhz

Output:
*******
R = 41.67 Ohms
L >= 1.592 uH
C >= 0.0637 nf ( 64pF => 68pF) {Usar 0.1uF}
P = 0.15W
I = 60 mA