How to increase signal noise ratio at the output signal?

[simo]

signal noise ratio

hi
i have a signal at the output of quadratur LNA,i do need to Combine this signal and increas signal noise ratio of that at the output signal.
pleas anyone has any schematic for that???

 

[simo]

Re: signal noise ratio

any idea guys?????

 

[mrm]

Re: signal noise ratio

Try with a quadrature hybrid circuit like a branch line hybrid combiner. Signals will sum in voltage and noise in power (sqrt(2) increase over SNR).
Bye Mrm

 

[hello_bob]

Re: signal noise ratio

Does signal is analogue or not?

 

[simo]

Re: signal noise ratio

the signals are analogue.
pleas if you have any schematic
send it to me
regards

 

[simo]

Re: signal noise ratio

any idea guys to increas the signal to noise ratio????

 

[flatulent]

Re: signal noise ratio

The only way to increase the SNR is to raise the signal level before the noise is added or reduce the added noise.

1. Use an amplifier with lower noise figure.

2. Raise the signal level at the source.

 

[mrm]

Re: signal noise ratio

try my previous suggestions: noise are uncorrelated and sum by power. Signals are correlated and sum by power. It's the principle of diversity receiption.

 

[activewei]

I presume you are talking about a receiver signal to noise ratio. What you need to concern is the front end circuit of the receiver. As flatulent explained, use lower noise figure amplifier as front end LNA. Try using lower insertion loss bandpass filter (if necessary) before LNA.