The enhancement of the output characteristics in the GaN based multiple‐channel planar Gunn diode

Abstract

We present an explicit numerical analysis on GaN‐based multi‐quantum‐well planar Gunn diodes. The simulation demonstrates that Gunn oscillations generated in the multi‐channel can be self‐synchronized to each other, which significantly improves the output characteristics of planar Gunn diode due to the superposition of the dipole domain in each channel. The optimized output characteristics are obtained in the triple‐channel Gunn diode, where the RF output power is about 6.45 mW and the DC‐to‐RF conversion efficiency is about 2.39% at the fundamental frequency of 216.05 GHz, more than three times larger than that of the single‐channel AlGaN/GaN Gunn diode. The proposed GaN HEMT‐like multi‐channel planar Gunn diode with higher level of output characteristics shows great potential as a solid‐state radiation source of millimeter‐wave and sub‐terahertz.

Physical-Based Simulation of the GaN-Based Grooved-Anode Planar Gunn Diode

“…The temperature is set to be 300 K, ideally. In order to calculate the RF output characteristics of the Gunn diode, we use the same method as explained in detail in [22][23][24].…”

“…The temperature is set to be 300 K, ideally. In order to calculate the RF output characteristics of the Gunn diode, we use the same method as explained in detail in [22][23][24]. In order to calculate the electrical characteristics of the diode, we put a single-tone sinusoidal voltage of form VDC + VACsin(2πft) across the diode instead of embedding it to a resonant circuit, as the external circuit adds complexity to the calculation and easily results in non-convergence.…”

“…Nevertheless, all of these emerging devices face the same serious problem-that is, how to generate sufficient RF power. Some theoretical work also shows other solutions, like the harmonic Gunn diode reported in [22,23] and the multi-channel Gunn diode in [24], which either suffers from low RF output power or a complicated process. In order to achieve higher frequency and higher output power simultaneously, for the first time, we propose this new-type grooved-anode Gunn diode, which is realized by simply etching a rectangle groove onto the semiconductor layer at one lithographic step.…”

Distribution of donor states on the surface of AlGaN/GaN heterostructures*

“…These models, which consider the electrons in the 2DEG coming from the surface donor states, have been widely used in the analysis of GaN based multiple-channel devices. [12][13][14] However, the precise features of donor states distribution on Al-GaN/GaN surfaces are still unclear. In previous reports, the density of surface donor states is constant over the range of energy levels.…”

Reliable GaN-Based THz Gunn Diodes With Side-Contact and Field-Plate Technologies

“…In [10], an efficient method to improve the crystal quality of GaN Gunn diode with AlGaN hot electron injecting layer on SiC substrate was reported. Multi-channel Gunn diode, which is realized by containing multiple AlGaN/GaN heterostructures as GaN-based HEMT-like planar Gunn diode improves the output power and the characteristics at a higher frequency, was proposed in [11]. In comparison to the prior works from other groups, the novelty of this work besides the GaN substrate is the side-contact and field-plate technologies for smaller effective diode width and height with better field distribution.…”