Low-voltage operation GaAs spike-gate power FET with high power-added efficiency

A GaAs power FET with a spike-gate has been developed for high-efficiency operation under extremely low supply voltage less than 1.5 V. The spike-gate provides both low on-resistance of 2.2 /spl Omega//mm and high transconductance of 180 mS/mm without reducing the output impedance or increasing the gate resistance. The implemented device achieved an output power of 31.5 dBm with 70% power-added efficiency at a frequency of 900 MHz. It should be noted that the present device kept PAE of 60% even at a bias of 0.5 V, which is the lowest voltage ever attained.