Emergency: Stabilization of LNA using resistor

I have designed an LNA; to stabilize my transistor. I added a series resistance of 20 ohms to make it unconditionally stable. Plz tell me if i m required to convert it to microstrip line also. for implementation.

Operating frequency 2.4 GHz

Q: how to convert a resistor to microstripline.

u could use a chip resistor of that value....it has a small dimension of about 1.5mm so any space considerations should not be affected...or you could use a think film resistor..

Is the series resistance before or after the LNA? It's likely before the LNA because there it's more effective. This is not a good approach as the series resistor in front of the amplifier will ruin your noise figure.

You cannot convert a resistor into microstrip sections. A resistor creates losses and is broadband, a microstrip stub or section only generates very small losses and is very frequency selective. But you could use the resistor embedded into the series microstrip line ...

Dear it is after the transistor, at the transistor. By doing this i made the transistor unconditonally stable. If had made that in series before the transistor noise deteioration was high but now it is stable. and nf is about 0.622dB. But the problem is my desired results are coming at 2.2 GHz rather than 2.4 GHz.

Teak the capacitors.

dear adeel1340,

Your r right about what you have written,

The stabilization resistor might hardly be mounted through the transistor output terminal. In order to avoid interference, stabilization resistor should be shifted at least 1 or 2 mm out from the transistor pad and the transmission line joining the pad has 0.8 mm wide. The stabilization is obtained with a transmission line and a shunt or series resistor.

good luck

N