Experimental verification of low-frequency noise effects at the onset of oscillations in planar Gunn diodes

In this work, the presence of an anomalous increase of low-frequency noise associated with the initiation of the oscillatory regime in Gunn diodes has been studied and experimentally evidenced. When incipient instabilities begin to appear in the device, its intermittent nature drastically enhances the noise at frequencies well below that of the oscillation. For higher bias voltages, the oscillation becomes purer and the associated low-frequency noise disappears.