smi.james.th
Newbie level 2
Hello all,
Newbie here. I am trying to build a 7GHz amplifier using the ATF-35143 pHEMT with matching that I designed myself. I don't have a lot of experience with discrete transistors and amplifiers in general, my previous work was more in passive RF.
When I apply a 7GHz tone to the input of the amplifier, after biasing it with V_DS 2V and I_DS at 5mA, I get a lot of strange "tones" at the output, as in the photo:
I made some I/V curves on the same transistor (without a source or a load attached) and this was the result:
What could make a transistor behave like that? I have a package of them, this is the third one I've tried all with fairly similar results. I don't know if there's something that I'm doing wrong to break the transistors, I have taken all reasonable precautions against static.
Thanks in advance.
James
Newbie here. I am trying to build a 7GHz amplifier using the ATF-35143 pHEMT with matching that I designed myself. I don't have a lot of experience with discrete transistors and amplifiers in general, my previous work was more in passive RF.
When I apply a 7GHz tone to the input of the amplifier, after biasing it with V_DS 2V and I_DS at 5mA, I get a lot of strange "tones" at the output, as in the photo:
I made some I/V curves on the same transistor (without a source or a load attached) and this was the result:
What could make a transistor behave like that? I have a package of them, this is the third one I've tried all with fairly similar results. I don't know if there's something that I'm doing wrong to break the transistors, I have taken all reasonable precautions against static.
Thanks in advance.
James