microwave amplifier using BJT 2sc3356 (NE85633)

My final year project is to design a microwave amplifier using BJT 2sc3356(NE85633), operation at 433MHz, with about 10dB gain and noise figure 1.5dB~2.5dB.

I use the simulation software ADS to perform simulation. The transistor model is the design kit dowloaded from NEC website.

Althought the simulation results is very good , the performance of the real product is very bad, the S21 is only about 2dB...

For this poor results, I have many question. Am I used the wrong biasing network? Am I has design the input and output matching network wrongly? Or I still have something mistake about using ADS?

Attached with the schematics for the amplifier and the ADS simulation result. Please have a look and feel free to critize it.

Re: Help for RF amplifier

The circuit is fine and the bias is ok also.
Check the real product for shorts on the board, or bad components, including the transistor.
Verify the DC current through the transistor, where should be approximately 8mA.

Re: Help for RF amplifier

Try taking out the inductors and put >200pF for all the caps.
The S-Parameters look like they should meet your specs with
just a 50 Ohm input & Output Loads (The Network Analyzer).

All the specs on the data sheet use 10V as Vce. You can try to increase
the Voltage from 5V to 10V.

Good luck.

Help for RF amplifier

Generally, serial capacitors are demaged when they are soldered and therefore the gain drops too much due to very small serial capacitor that rests..
And also, a small soldering piece can create a -like short- circuit for RF frequencies...
There may be some such different errors

Help for RF amplifier

RF design include proper layout.
If layout is not carefully done, this can also happen.
If you post it, we can have a look.

Mazz

Help for RF amplifier

Thank you for the above advice. I would like to ask one more thing is there anyone can help me to check whether my design method is correct:
1. plot the noise and gain circle in smith chart, find out the intersection point of the desire gain and noise circle. Also need to make sure the point is out of the source stability circle region. The impedance from the intersection point is use to design the input matching network. Which is use to match the source matching to the input impedance of the transistor.

2. After desiging the input matching network. I have a problem in designing the output matching network. What is the requirement of the output network? Shall I decided the point in the SmithChart which is out of the load stability region? Or the point should be conjugate the output reflection coefficient of the transistor?

Thanks a lot!