Derivative superposition method for DG MOSFET application to RF mixer

A high linear double-gate (DG) MOSFET application to RF mixer is proposed based on derivative superposition method which was successfully used in Bulk CMOS region. By independently biasing front and back gate voltage of DG MOSFET, one DG MOSFET device is reviewed as two parallel devices. In this way, we realize the derivative superposition method application in the DG MOSFET linearity analysis and high performance RF mixer. Via two-dimensional (2D) TCAD device simulation and through the third-order transconductance (g_m3) cancellation, we get some interesting results of DG MOSFET mixer different from the Bulk CMOS mixer. It is found that the DG MOSFET is suitable to work as a single device mixer because of coupling effect of two gates, e.g., a high linear independent DG MOSFET mixer shows 7.8dB improvement on IIP3 corresponding to the symmetrical DG mixer with the same DC current. The relationships between the amplitude of LO signal, the conversion gain and linearity are also analyzed in this paper.