A simple analysis of the stable field profile in the supercritical TEA

An analytical investigation supported by numerical calculations has been performed of the stable field profile in a supercritical diffusion-stabilized n-GaAs transferred electron amplifier (TEA) with ohmic contacts. In the numerical analysis, the field profile is determined by solving the steady-state continuity and Poisson equations. The diffusion-induced short-circuit stability is checked by performing time-domain computer simulations under constant voltage conditions. The analytical analysis based on simplifying assumptions gives the following results in good agreement with the numerical results. 1) A minimum doping level required for stability exists, which is inversely proportional to the field-independent diffusion coefficient assumed in the simple analysis. 2) The dc current is bias independent and below the threshold value, and the current drop ratio increases slowly and almost linearly with the doping level. 3) The domain width normalized to the diode length
L
varies almost linearly with
(V_{B}/V_{T}-1)^{\frac{1}{2}}/(n_{0}L)^{\frac{1}{2}}
where V
B
is the bias voltage V
T
is the threshold voltage, and no is the doping level. 4) The peak domain field varies almost linearly with (
V_{B}/V_{T}-1
)^{\frac{1}{2}} (
n_{0}L)^{\frac{1}{2}}
. Those results contribute to the understanding of the high
n_{0}L
-product switch and the stability of the supercritical TEA.