Modelling of Gunn-domain effects in GaAs m.e.s.f.e.t.s

Modeling of gunn domain effects in the output conductance of the high‐frequency small‐signal GaAs MESFET equivalent circuit

“…The element values of the MESFET equivalent circuit (see Figure 2 ) fitted for the FLR016XV device at the VDDID3 point are written in Table 1. Figure 5 shows the fitted S parameters for this bias point with the Tgds model and the model in [5] and can be compared to Figure 1. The discrepancy in the S2, magnitude has been eliminated using our model.…”

“…which is approximately 26 GHz for the L,R de Figure 1 using the model of Figure 2. S2, fit [5] corresponds to the model of Reference [5] using [I31 and Rdom = -937 a, C , , , = 2 fF, C,, = 60 fF, g,, = 3.5 mS, T~,, = 0, with the remaining element values approximately same as from Table 1 frequency of oscillation [15] for this device example using the model of [l] is approximately 73 GHz.…”

“…In this representation the domain resistance can be absorbed within the output conductance, the domain capacitance can be added to Cd,, and the frequency variation in S22 is not predicted. A shunt R-C network with a negative resistance value to account for a negative slope in the dc I-V curves has also been proposed [5] to model the Gunn domain effects.…”

A Novel Schmitt-Trigger Circuit with GaAs MESFETs

“…Theoretical and experimental investigations show that GaAs MESFETs can have a negative output resistance [4] and in [3] already a hint is given to use this property to build up a device with a hysteresis characteristic. circuit is described with a transfer characteristic close to an ideal step function.…”