n3x
Newbie level 3
Hello,
I'm doing a university project and it is my first time to work on amplifiers (or any hardware at all) and I have run at some problem I cannot solve.
My assignment is to build a broadband amplifier, using a gain block circuit and a selective amplifier using a transistor.
I designed the circuits in and simulated them in Qucs to get the wanted results.
However when I measure, between the results and simulation, there is quite a difference:
- Broadband amplifiers gain is both lower than simulated and declining in the part it should be level
- Sel Amp has similar shape to the simulated, but the gain at design frequency is 11db vs 17db(simulation)
Somethings that could cause small differences:
-the substrate could be with er 4.4+/- 0.1
-the amplifier leads are not connected to the center of of the microstrips
-the matching stubs in the sel amp may be not at the exact place as calculated
Can someone suggest a possible explanation for big differences, because I have run out of ideas.
Thanks in advance
I'm doing a university project and it is my first time to work on amplifiers (or any hardware at all) and I have run at some problem I cannot solve.
My assignment is to build a broadband amplifier, using a gain block circuit and a selective amplifier using a transistor.
I designed the circuits in and simulated them in Qucs to get the wanted results.
However when I measure, between the results and simulation, there is quite a difference:
- Broadband amplifiers gain is both lower than simulated and declining in the part it should be level
- Sel Amp has similar shape to the simulated, but the gain at design frequency is 11db vs 17db(simulation)
Somethings that could cause small differences:
-the substrate could be with er 4.4+/- 0.1
-the amplifier leads are not connected to the center of of the microstrips
-the matching stubs in the sel amp may be not at the exact place as calculated
Can someone suggest a possible explanation for big differences, because I have run out of ideas.
Thanks in advance