low noise amplifer

Thread Starter

vicky_13

Joined Nov 24, 2008
1
hey i have to design a 2 stage low noise amplifier using 2QN3906 in orcad capture.For that i need a circuit with all its values of capacitor,resistor etc.can any body give me any cuircuit of low noise amplifier with all specifications.
 

beenthere

Joined Apr 20, 2004
15,808
Simply use better quality components - film resistors and poly capacitors. The 2N3906's aren't particularly rated as low noise devices, so all you can do is use good passives and pay attention to layout.

We will help with your design, but we are not a design service.
 

KL7AJ

Joined Nov 4, 2008
2,208
hey i have to design a 2 stage low noise amplifier using 2QN3906 in orcad capture.For that i need a circuit with all its values of capacitor,resistor etc.can any body give me any cuircuit of low noise amplifier with all specifications.

As a general, using low resistances and low currents will reduce the overall noise. However, as you probably noticed, these are two conflicting, contradictory requirements. Balancing these for overall noise improvmement can be a bit of an art form.

However...using circuits like common gate (or common base) instead of common emitter amplifiers, can do a lot to reduce noise by matching at a lower impedance.

A "cascode" amplifier is a high gain amplifier that has good noise and gain performance.

eric
 
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