A novel MMIC power amplifier using cascode FET with unequal gate widths

A novel MMIC power amplifier that uses a cascode FET with unequal gate widths is presented. The amplifier uses a new concept of self phase distortion compensation. By enlarging the gate widths of a common-source FET, output phase deviation can be improved without reducing the gain and output power. A prototype PA achieves the high power added efficiency of 50 % at the drain supply voltage of 3.5 V with sufficient linearity for the 1.9-GHz Japanese Personal Handy-phone System.