Fabrication and Characterisation of GaAs Gunn Diode Chips for Applications at 77 GHz in Automotive Industry

Abstract

GaAs-based Gunn diodes with graded AlGaAs hot electron injectorheterostructures have been developed under the special needs in automotive applications.The fabrication of the Gunn diode chips was based on total substrate removal andprocessing of integrated Au heat sinks. Especially, the thermal and RF behavior of thediodes have been analyzed by DC, impedance and S-parameter measurements. Theelectrical investigations have revealed the functionality of the hot electron injector. Anoptimized layer structure could fulfill the requirements in adaptive cruise control (ACC)systems at 77 GHz with typical output power between 50 and 90 mW

Reduction of Impact Ionization in GaAs-Based Planar Gunn Diodes by Anode Contact Design

“…It is observed that the I-V curves flatten for voltages above a value of around ~3 V in both cases. This behaviour is normally attributed to the occurrence of a significant intervalley scattering in the device channel [6,7,9]. It is also observed that the current is somewhat higher (~15-25%) in the device with all-ohmic contacts, in both the linear and the saturation regimes.…”

“…Gunn diodes can generate continuous wave signal with low phase noise in the GHz range, with output powers up to 100 mW [5,6,7]. Thus, they are good candidates for mm-wave and THz emission, provided their operation frequency can be extended into the THz regime.…”

Gunn oscillator modeling and second harmonic output power optimization at 76 GHz

“…Parameters I th , E th , and (nl d ) are the threshold current, threshold field and the doping density/active device length-product given by the manufacturer [13]- [15]. The last parameter, µ is the Sensitivity analysis shows that the output power changes only slightly if different estimates for the Gunn device impedance are used and that this simulation approach can be used even without exact estimates for the Gunn device impedance.…”

Isothermal measurement of current-voltage characteristics of Gunn diodes with reflection of their discontinuities and hysteresis

“…First, the I-V characteristic in the region before the threshold voltage is very sensitive to self-heating of the active area (i.e., it depends on the test pulse duration). In [2], the results of measurements of I-V characteristics at pulse durations from 100 ns are presented. According to our estimates ( Fig.…”