Help with circuit in ADS
时间：04-07
整理：3721RD
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Hello I still working in project about mixer, but I have problem with the simulations, I read some papers, but I do not find my mystake.
My problem is: I add two signals at GATE of BF998, but I do not see the diferencies about this signals on the output MOSFET I could not see the differences in the entry signals. Maybe I need to put some parameter that I am omitting. The design is I it working but I need simulate these results, I hope you can help me.
My problem is: I add two signals at GATE of BF998, but I do not see the diferencies about this signals on the output MOSFET I could not see the differences in the entry signals. Maybe I need to put some parameter that I am omitting. The design is I it working but I need simulate these results, I hope you can help me.
That means your mixer does not work. Did you check the design?
Why do the 2 input signals power show similar power level? As I know, usually there is a low power frequency input.
-You can not connect the signal source without DC blocking capacitors otherwise bias will be short circuited with source impedance e.g. 50 Ohm.. Your bias flies away..
-You can not connect your sources by simply parallel connection because they will influence each other..
-The source impedances are define in properties dialog of source, you shouldn't connect a extra resistor in parallel.
-For N-MOS transistors, VGS must be positive ( E-Mode ) so your VGS bias circuit is not correct.But If you have used D-Mode devices, it's OK, it may work..