140 GHz GaAs double-Read IMPATT diodes

Banerjee

2012

Appl Nanosci

In this paper the potentiality of impact avalanche transit time (IMPATT) devices based on different semiconductor materials such as GaAs, Si, InP, 4H-SiC and Wurtzite-GaN (Wz-GaN) has been explored for operation at terahertz frequencies. Drift-diffusion model is used to design double-drift region (DDR) IMPATTs based on different materials at millimeter-wave (mm-wave) and terahertz (THz) frequencies. The performance limitations of these devices are studied from the avalanche response times at different mm-wave and THz frequencies. Results show that the upper cut-off frequency limits of GaAs and Si DDR IMPATTs are 220 GHz and 0.5 THz, respectively, whereas the same for InP and 4H-SiC DDR IMPATTs is 1.0 THz. Wz-GaN DDR IMPATTs are found to be excellent candidate for generation of RF power at THz frequencies of the order of 5.0 THz with appreciable DC to RF conversion efficiency. Further, it is observed that up to 1.0 THz, 4H-SiC DDR IMPATTs excel Wz-GaN DDR IMPATTs as regards their RF power outputs. Thus, the wide bandgap semiconductors such as Wz-GaN and 4H-SiC are highly suitable materials for DDR IMPATTs at both mm-wave and THz frequency ranges.

Section: High-frequency Propertiesmentioning

confidence: 75%

Prospects of IMPATT devices based on wide bandgap semiconductors as potential terahertz sources

Banerjee

2012

Appl Nanosci

“…Variation of RF power output ( P RF ) of DDR G‐IMPATT devices (under PCPC mode consisting of N = 10 parallel connected diodes) with operating frequency, considering r α = 1.0 is shown in Figure . The same figure also shows the variations of P RF of IMPATT sources based on Wz‐GaN, 4H‐SiC, type‐IIb diamond, GaAs, InP, and Si with frequency obtained from simulation as well as experimental measurements (where available in literature) . The rate of decrease of the RF voltage with operating frequency is found to be much greater that the rate of increase of the magnitude of the negative conductance with respect to the frequency (| dV rf / df | >> | dG p / df |); that is why the RF power output is bound to decrease with the increase of the operating frequency.…”

Section: Characteristics Of G‐impatt Sourcesmentioning

confidence: 88%

1.0–10.0 THz Radiation from Graphene Nanoribbon Based Avalanche Transit Time Sources

Physica Status Solidi (a)

2019

The possibilities of terahertz frequency generation by using graphene nanoribbon (GNR) based avalanche transit time (ATT) sources are investigated in this paper. The most promising candidate of ATT device family, i.e., the impact avalanche transit time (IMPATT) diode is chosen for the present study. Parallel connected GNR based IMPATT structures with inherent power combining capability are proposed and simulated by using self-consistent quantum drift-diffusion model based in-house simulation codes in order to study the static, high frequency and noise performance of those at different millimeter-wave and terahertz frequency bands. The detailed study reveals that the in-build power combined GNR IMPATT sources are capable of performing more efficiently than the IMPATT sources based on some other popular semiconductor materials as well as some state-of-the-art terahertz radiators within the terahertz frequency band from 1 to 10 THz.

“…In the same figure the simulated and experimentally measured power outputs of IMPATT sources based on Si, GaAs, InP, type-IIb diamond and Wurtzite (Wz)-GaN are also shown. [39][40][41][42][43][44][45][46][47][48] It is interesting to observe from Figure 13 that the power output of ten-element mutually injection locked G-IMPATT source exceeds the power output of most promising Wz-GaN IMPATT source when the frequency of operation increases up to 5.0 THz. Therefore, mutually injection locked N-element (N ≥ 10) G-IMPATT sources operating in PCPC mode is the best choice for generating THz frequencies greater than 5.0 THz.…”

Section: F I G U R Ementioning

confidence: 98%

Terahertz wave radiation from mutually injection locked multi‐element graphene nanoribbon avalanche transit time sources

Int J Numerical Modelling

2020

Mutual injection locking of multi-element graphene nanoribbon impact avalanche transit time (G-IMPATT) sources designed to operate at different millimeter-wave (mm-wave) and terahertz frequencies has been studied. Planar circuit is used for implementing the mutual injection locking between adjacent elements of the source operating in parallel-connected-powercombined mode. The static, high frequency and noise simulations of the proposed sources have been carried out by using in-house simulation codes based on self-consistent quantum drift-diffusion model. Results show that mutual injection locking between the adjacent elements forced the sources to oscillate nearly at a single frequency even if significantly high degree of mismatch is present among the elements of the multi-element oscillators. A minor amount of reduction in power out and insignificant deterioration in the noise performance of the multi-element G-IMPATT oscillators have been observed due to the presence of mutual injection locking between the adjacent elements.