Rf power transistor having off-axis layout

Abstract

A high frequency RF power transistor includes first and second elongated mesas. In one example, the transistor is part of a millimeter wave MMIC power amplifier. From the top-down perspective, the two mesas are disposed in an off-axis and staggered orientation with respect to one another. A branched gate electrode is formed such that a first branch from a gate signal input location to the first mesa is the same length as a second branch from the input location to the second mesa. Likewise, a branched drain electrode is formed such that a first branch from the first mesa to a drain signal output location is the same length as a second branch from the second mesa to the output location. The off-axis and staggered orientation of the mesas spreads heat generation across the integrated circuit and reduces circuit size in the critical dimension perpendicular to signal flow direction.