Design of Low noise GHz amplifier

[fadaontop]

Good day, pls am a student and am working on design of low noise amplifier with frequency 2.0-2.5Ghz .. pls how do i go about it. Thanks

 

[OLIVE2222]

You give very few information's but as first shot I will have a look on MMICs as they are easy to implement. They are many manufacturer , mini-circuits, CEL, Avago, triquint ....
Olivier

 

[fadaontop]

@ Olie2222....Am plaining using proteus 7 to design it..I will definitely use a good RF transistor that can handle the specified frquency range... What i still dont get is how to introduce an input frequency to the transistor ... i mostly come across 50ohm impedance as source in my readings but i dont know how to introduce it to the design

 

[OLIVE2222]

I am not an expert in HF stuff. I generally think in term of building blocks or single IC solution in this area.
The only information I have is the following datasheet on wich you can see the way to get 50 ohms input impedance.

http://www.eurotech.co.uk/data/SL560.pdf

Hope that a HF guru will take over your post.
Olivier

 

[davenn]

Greetings fadaontop
welcome to the forums

Although MMIC's are great at SHF frequencies, they are much better for low power transmit amplifier stages rather than low noise receiver preamplifiers. This is mainly because they are relatively noisy. You will be hardpressed to find one that has better than ~ 1.5 - 2 dB noise figure.
You are better off with a standalone GaAsFET device as you will then be able to achieve noise figures down to 0.3 - 0.5 dB. The final NF achieved is primarily related to the quality of your design and circuit construction.

Digging into my files I found a typical circuit for GaAsFET amplifiers, see the attached files the first one shows an amp up to 3.4 GHz
the second page has info on the power/biasing requirements

cheers
Dave