gilbert mixer
To Hello,
In a CMOS balanced Gilbert cell mixer, M3 to M6 because they are operating as a switch, is baised at Vds = Vgs - Vt.
M3 to M6 have the same devices characteristics(W/L , Cox and so on) and since 2 of the FET are operating at any time with their drain current being equal, their drain current is Iss/2. Iss being the current from Vdd.
Being in the saturation region, for M3 to M6 their equation is Id = K(W/Y)Sqr(Vgs-Vt).
M1 and M2 act as a differential amplifier. Their drain current is from M3 to M6. Being in the saturation region and have the same devices characteristics(W/L , Cox and so on), their equation is Id = K(W/Y)Sqr(Vgs-Vt).
Does this mean that M1 and M2 have the same W/L as M3 to M6?
Thanks.
T.P. Puah