Gunn,'s Device Nonlinear Model And Its Application

Gunn oscillator plays an important role in millimeter system actually and it is widely used due to its advantages such as low AM noise. Gunn oscillator is cheaper and has more concise structure than millimeter multiplier in high frequency band.According to the knowledge of semiconductor and mathematics, the relationship between the total current in the Gunn diode and driven voltage can be found in light of Poisson's equation and the continuity of total current, so can be physical mechanism and working modes of diode chip, which leads to establishment of nonlinear circuit of GaAs Gunn diode chip. This model interprets the nonlinear harmonic character of Gunn diode and the output spectrum is gotten by ADS as well as the relation between driven voltage and output power. All of the works we have done give some improvement to analyses of inner Gunn diode.With respect to construction of the outer circuit of Gunn oscillator, it is the equivalent circuit measure, which calculates the whole outer circuit, making parameters of outer circuit summed up on the Gunn diode side by means of transmission line theory, that, illustrates which parameters actually influence the match between inner diode and outer circuit so as to facilitate our design and adjustment, as the result of using MATLAB and considering balance theory of oscillator.Finally, taking advantage of the analyses we have made above, we have designed a GaAs Gunn oscillator. Its output power is approximately 2mW at 112GHz.