low noise amplifier for KA band

hi, I am new to amplifier design. I am doing a low noise amplifier design and implementation for my final year project of undergraduate studies. I need to design a low noise amplifier at KA band downlink frequency range(18.3GHz -18.8GHz or 19.7GHz - 20.2GHz). It must be implemented using microstrip
(FR4,er =4.5). I need suggestions on what model of amplifier(transistor) to use for the design?I also hope u guys can provide me with some guides and example schematics for the design?
thanks

as far as i know , the FR4 material can't be used in this frequency range , the loss in FR4 material is very high , acutually it is very hard to use it about 4 GHz , not 18

for your range u need check Taconic TLY , and Duriod

about the transistors did u checked filtronics , and Cel , and NEC

khouly

Hi,

FR4 might not be a good choice for the frequency range you have, it is very lossy at those frequencies. However, this is very cheep substrate so perhaps minimizing cost is the target of your design project.

Typically there isn't an example schematic for the problem you are working on, after some theory studying you will come to the schematic yourself. The underlying theory could be found in the textbooks:

Guillermo Gonzalez ?
Microwave Transistor Amplifiers - Analysis and Design, Second Edition, Prentice Hall, 1997

George D. Vendelin, Anthony M. Pavio, Ulrich L. Rohde, -
Microwave Circuit Design Using Linear and Nonlinear Techniques,
John Wiley & Sons, 1990

or

George D. Vendelin, Anthony M. Pavio, Ulrich L. Rohde, -
Microwave Circuit Design Using Linear and Nonlinear Techniques,
Second Edition, John Wiley & Sons, 2005

flyhigh

for the duroid microstrip you suggested, what should be the thickness and other physical characteristics?

Kindly disagree. FR4 with known epsilon and good design works ok at 10GHz.
At 5.5Ghz FR4 is used extensively on WIFI/WIMAX (non licensed) boards.
However is not recommended above 10Ghz.