tomrett
Newbie
Hello forum,
im trying to design a Gilbert cell mixer and im stuck on one requirement.
Background: the RF differential voltage swing should above 900mVpp (currently RF=991.2mVpp). This swing must remain the same. IFm and IFp are equal to 20mVpp while the IF signal frequency is set to 1MHz with a DC voltage level of 1.6V. LOp is equal to a DC voltage of 2.7V while LOm is equal to a DC voltage of 2.4V. The power supply voltage VCC is equal to 3.3V.
Im now interested to achieve the following requirement: achieve linear operation for IF differential input voltage swing of 800mVpp. I know i have to use emitter-degeneration, but im not sure how do achieve this, while keeping the RF differential voltage swing above 900mVpp.
What i have tried so far: I tried using a resistor (84.5 Ohm) at the Emitter to increase the voltage drop, but this somehow resulted in a lower voltage drop at IFm_d (i can upload a photo of my derivation, if required).
Has anyone any suggestions? Im fairly new to this topic and i would be happy to receive any helpful input on this.
Thanks!
im trying to design a Gilbert cell mixer and im stuck on one requirement.
Background: the RF differential voltage swing should above 900mVpp (currently RF=991.2mVpp). This swing must remain the same. IFm and IFp are equal to 20mVpp while the IF signal frequency is set to 1MHz with a DC voltage level of 1.6V. LOp is equal to a DC voltage of 2.7V while LOm is equal to a DC voltage of 2.4V. The power supply voltage VCC is equal to 3.3V.
Im now interested to achieve the following requirement: achieve linear operation for IF differential input voltage swing of 800mVpp. I know i have to use emitter-degeneration, but im not sure how do achieve this, while keeping the RF differential voltage swing above 900mVpp.
What i have tried so far: I tried using a resistor (84.5 Ohm) at the Emitter to increase the voltage drop, but this somehow resulted in a lower voltage drop at IFm_d (i can upload a photo of my derivation, if required).
Has anyone any suggestions? Im fairly new to this topic and i would be happy to receive any helpful input on this.
Thanks!
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![](data:image/svg+xml;charset=utf-8,<svg height="891px" width="814px" xmlns="http://www.w3.org/2000/svg" version="1.1"/>)