RESONANT TUNNELING DIODE IMMEDUNCE DEPENDENCE ANALYSIS

The impedance dependence of resonant tunneling diode (RTD) based on InGaAslInAlAs heterostructure was measured in 0.1 ... 50 GHz frequency range. It is shown, that the simplest equivalent circuit, consisting of parallel resistor and capacitance and connected to them in series resistor, describes the experimental behavior rather well. The RTD equivalent circuit parameters dependences on applied bias were obtained and standard deviations of these parameters were evaluated with methods of mathematical statistics. The RTDs based on double-barrier heterostructures are intensively investigated due to their promises for application in microwave, optoelectronics and high-speed electronics [I]. They are now one of the most highspeed devices. The other unique properties of RTD are the capability to change the current voltage curve form by varying the thickness and composition of RTD active layers and the effect of noise suppression on the ascending part of RTD I-V curve. For various applications it is necessary to know the RTD small signal equivalent circuit. At present time several RTD equivalent circuits are known [2-51, however there is no procedure that allows choosing the equivalent circuit for concrete RTD in the best way. In this letter we used the nonlinear regression method to determine parameters of the RTD equivalent circuit. The method consists in follows. At pointsj (i = I...n) uniformly distributed from 0.1 to 50 GHz the RTD impedance Z&, v) was determined experimentally, where V is applied to RTD bias voltage. At the same fi’ the impedance Z,fJ of proposed RTD equivalent circuit was calculated and the following goal function was constructed