Measured equivalent gate noise voltage spectra of 1-µm gate-length MODFET\´s, for the frequency range of 0.01 Hz-100 MHz, are presented. They indicate that the noise consists of several high-intensity trap-related generation-recombination (g-r) noise components superimposed on a background

noise. The g-r noise is reduced when the Al mole-fraction is lowered. The same occurs when the gate reverse bias is increased. At 100 K the g-r noise bulge moves towards subaudio frequencies clearly revealing the

noise.