A Rigorous Comparison of Package and PCB Effects on Micromixer- and Gilbert Mixer-Based Upconverter MMICs

A Volterra series analysis is presented to study the package and printed circuit board (PCB) effects on the linearity of two W-CDMA upconverter MMIC designs. The first design adopts a recently popular micromixer with class-AB input stage. The second design is based on a commonly used Gilbert mixer with emitter degeneration. Both upconverter MMICs are designed to have the same adjacent channel power ratio (ACPR) in the chip-level simulation. After fabrication, packaging and testing on PCB, the micromixer-based design consumes less direct current but causes more degradation in the ACPR performance due to the influence of package and PCB when compared to the Gilbert mixer-based design. The analysis indicates that the micromixer-based upconverter MMIC is rather susceptible to the parasitic effects from the ground interconnect, and therefore it needs a better package solution with a lower ground inductance for practical use.