I need help to get the desired S-parameter for low noise amplifier

Dear Sir,
I designed the biasing for the low noise amplifier at Vds=3v, Ids=20mA, need to get the desired s- parameter as follows

f(GHz) s11(dB) S21(dB) S12(dB) S22(dB)
1.3 -1.83312 17.944 -23.083 -10.637

But I am obtaining the following S-parameter values

f(GHz) s11(dB) s21(dB) s12(dB) s22(dB)
1.3 -0.012809 11.721 -86.024 -2.1229

Can anybody help me to get the desired s-parameter low noise amplifier, Here with I am attaching the schematic of the lna

btv_murthy said:

Dear Sir,
I designed the biasing for the low noise amplifier at Vds=3v, Ids=20mA, need to get the desired s- parameter as follows

f(GHz) s11(dB) S21(dB) S12(dB) S22(dB)
1.3 -1.83312 17.944 -23.083 -10.637

But I am obtaining the following S-parameter values

f(GHz) s11(dB) s21(dB) s12(dB) s22(dB)
1.3 -0.012809 11.721 -86.024 -2.1229

Can anybody help me to get the desired s-parameter low noise amplifier, Here with I am attaching the schematic of the lna

Click to expand...

Your s11 measurement, which is a measure of the amount of energy reflected back from your input is very high. That means almost no power at 1.3 GHz is being transmitted into the amplifier. The same thing is happening with your output port, though not as badly.

The most likely design reason for the poor return loss performance is an impedance mismatch at the port. Let's assume you've intended to design your amplifier for 50 ohms. Either your cable you're using to measure your s parameters is not 50 ohms, or your amplifier ports are not 50 ohms.

Assuming your design is the issue, use your network analyzer to measure the port impedance. Make the necessary changes to your design to get the ports to match better to 50 ohms.

When you have designed a good match, your s11 will be greatly reduced, and you will see that as an increased value of s21 as well--assuming you've also improved your output port.

Dear Sir,
The S11 is company defined high reflected energy ,that is -1.83322. I obtained for my design is -0.01289 of the gain 11.721. what component I have to use for the input and output matching and what are the design values.

btv_murthy said:

Dear Sir,
The S11 is company defined high reflected energy ,that is -1.83322. I obtained for my design is -0.01289 of the gain 11.721. what component I have to use for the input and output matching and what are the design values.

Click to expand...

For the design procedure you can refer any tutorial from INTERNET. But by observing your S-parameters i can say that the input and the output ports are not matched. You can verify this by checking at what frequency does the input resonates with the values of those Inductors.
You could go for inductors because you haven't used any inductors in the input side so that remains Unmatched!!!!