Effect of Tunneling on Small Signal Characteristics of IMPATT Diodes with SiC Heteropolytype Structures

2019 ◽  
Vol 954 ◽  
pp. 176-181
Author(s):  
Ming Chang He ◽  
Li Xia Hu ◽  
Jun Ding Zheng ◽  
Wen Sheng Wei ◽  
Hai Lin Xiao ◽  
...  
Keyword(s):  
Transit Time ◽  
Small Signal ◽  
Large Power ◽  
Static State ◽  
Signal Characteristics ◽  
Atmospheric Window ◽  
Frequency Relation ◽  
The Impact ◽  
Peak Value ◽  
Impatt Diodes

SiC heteropolytype structures indicate important applications in high frequency, large power solid devices etc. In this paper, the impact avalanche transit time (IMPATT) and mixed tunneling avalanche transit time (MITATT) diodes with heteropolytype consisting of two semiconductors among the 3C-SiC, 4H-SiC and 6H-SiC are numerically simulated to investigate the static state and small signal characteristics at the atmospheric window frequency of 1.56 THz. The breakdown voltage, avalanche voltage, peak value of static electric field, the maximum generation rates of avalanche and tunneling, power conversion efficiency, admittance-frequency relation of the proposed SiC heteropolytype diodes are calculated, respectively. Comparing the obtained parameters of IMPATT diodes with those of MITATT devices, the results imply that tunneling shows little influence on the small signal performance of the heteropolytype IMPATT diodes included 3C-SiC material, which is different from those of the homopolytype counterparts.

Optimal Design of Large Signal and Noise Performance of GaN/SiC Hetero-Structural IMPATT Diodes Based on QCDD Model

2020 ◽  
Vol 1014 ◽  
pp. 68-74
Author(s):  
Jun Ding Zheng ◽  
Wen Sheng Wei ◽  
Wei Bo Yang ◽  
Chang Li
Keyword(s):  
Electric Field ◽  
Drift Region ◽  
Large Signal ◽  
Tunnel Current ◽  
Large Power ◽  
Static State ◽  
Frequency Relation ◽  
The Impact ◽  
Lower Noise ◽  
Impatt Diodes

Successes of GaN and SiC electronics in high frequency, large power realm indicate that, the GaN/SiC hetero-structures can be used to design the impact avalanche transit time (IMPATT) diodes operating at Terahertz range, of which holds advantages over homo-structural counterparts in lower noise and reduced tunnel current. Here, the (n)GaN/(p)SiC and (p)GaN/(n)SiC double drift region (DDR) IMPATT diodes operating at 0.85 THz are proposed based on the quantum corrected drift-diffusion (QCDD) model, the performance parameters of static state, large signal and noise properties of the studied devices such as peak electric field intensity, breakdown voltage, optimal negative conductance, output power, conversion efficiency, admittance-frequency relation, quality factor, noise electric field, mean-square noise voltage per band-width and noise measure were numerically calculated and analyzed, which can guide to optimize the GaN/SiC IMPATT diodes.

Optimal Design of Large Signal Performance of AlN/GaN Hetero-Structural IMPATT and MITATT Diodes

2020 ◽  
Vol 1014 ◽  
pp. 157-162
Author(s):  
Ping Wu ◽  
Wen Sheng Wei ◽  
Jun Ding Zheng ◽  
Wei Bo Yang ◽  
Chang Li ◽  
...  
Keyword(s):  
Optimal Design ◽  
Transit Time ◽  
Large Signal ◽  
Low Loss ◽  
Large Power ◽  
Static State ◽  
Hetero Structure ◽  
Signal Characteristics ◽  
Significant Difference ◽  
Frequency Relation

Hetero-structure of AlxGa1-xN/GaN exhibits important applications in high frequency and large power devices. In this paper, AlN/GaN is adopted to optimal design the large power impact avalanche transit time (IMPATT) and mixed tunneling avalanche transit time (MITATT) diodes operating at the atmospheric low loss window frequency of 0.85 THz. The static state and large signal characteristics of the devices are numerically simulated. The values of peak electric field strength, break-down voltage, avalanche voltage, the maximum generation rates of avalanche and tunneling, admittance-frequency relation, output power, conversion efficiency, quality factor of the proposed hetero-structural IMPATT and MITATT diodes are calculated, respectively. Via comparing the obtained results of (n)AlN/(p)GaN and (n)GaN/(p)AlN IMPATT diodes to those of the MITATT counterparts, there exists little performance difference between IMPATT and MITATT devices while implies significant difference between the (n)AlN/(p)GaN and (n)GaN/(p)AlN diodes.

Simulation on Large Signal and Noise Properties of (n)Si/(p)SiC Heterostructural IMPATT Diodes

2019 ◽  
Vol 954 ◽  
pp. 182-187 ◽  
Author(s):  
Jun Ding Zheng ◽  
Wen Sheng Wei ◽  
Jian Zhu Ye ◽  
Wei Bo Yang ◽  
Chang Li ◽  
...  
Keyword(s):  
Electric Field ◽  
Integrated Circuit ◽  
Drift Region ◽  
Large Signal ◽  
Static State ◽  
Atmospheric Window ◽  
Frequency Relation ◽  
Negative Conductance ◽  
Thz Power ◽  
Impatt Diodes

Si/SiC heterostructural impact avalanche transit time (IMPATT) diode indicates of important applications in Terahertz (THz) power source, integrated circuit etc. In this paper, the (n)Si/(p)4H-SiC, (n)Si/(p)6H-SiC, (n)Si/(p)3C-SiC heterostructural double drift region IMPATT diodes operating at the atmospheric window frequency of 0.85 THz are designed by the drift-diffusion model while their static state, large signal and noise properties are numerically simulated. The performance parameters of the studied devices such as breakdown voltage, peak electric field strength, optimal negative conductance, output power, power conversion efficiency, admittance-frequency relation, quality factor, noise electric field, mean-square noise voltage per band-width and noise measure were calculated and compared. This method can guide for optimizing the Si/SiC heterostructural IMPATT device in the future.

Terahertz Radiators Based on Si~3C-SiC MQW IMPATT Diodes

2020 ◽  
Vol 10 (4) ◽  
pp. 501-506
Author(s):  
Monisha Ghosh ◽  
Arindam Biswas ◽  
Aritra Acharyya
Keyword(s):  
High Frequency ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Noise Performance ◽  
Rf Power ◽  
Drift Diffusion ◽  
Frequency Bands ◽  
Atmospheric Window ◽  
Lower Noise ◽  
Impatt Diodes

Aims:: The potentiality of Multiple Quantum Well (MQW) Impacts Avalanche Transit Time (IMPATT) diodes based on Si~3C-SiC heterostructures as possible terahertz radiators have been explored in this paper. Objective:: The static, high frequency and noise performance of MQW devices operating at 94, 140, and 220 GHz atmospheric window frequencies, as well as 0.30 and 0.50 THz frequency bands, have been studied in this paper. Methods: The simulation methods based on a Self-Consistent Quantum Drift-Diffusion (SCQDD) model developed by the authors have been used for the above-mentioned studies. Results: Thus the noise performance of MQW DDRs will be obviously better as compared to the flat Si DDRs operating at different mm-wave and THz frequencies. Conclusion:: Simulation results show that Si~3C-SiC MQW IMPATT sources are capable of providing considerably higher RF power output with the significantly lower noise level at both millimeter-wave (mm-wave) and terahertz (THz) frequency bands as compared to conventional flat Si IMPATT sources.

scholarly journals A quantitative description of the spatial–temporal distribution and evolution pattern of world cultural heritage

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Liang Yongqi ◽  
Yang Ruixia ◽  
Wang Pu ◽  
Yang Anlin ◽  
Chen Guolong
Keyword(s):  
Cultural Heritage ◽  
World Heritage ◽  
World Heritage Site ◽  
Heritage Sites ◽  
Evolution Pattern ◽  
Modelling Analysis ◽  
Time Series Modelling ◽  
World Cultural Heritage ◽  
The Impact ◽  
Peak Value

AbstractDepicting the temporal and spatial evolution pattern of global world cultural heritage systematically and finely is the basis of heritage recognition and protection. In this study, 869 world cultural heritage inscriptions (through 2019) were selected as the research objects, and the times and types of each World Heritage site were manually annotated from more than 5000 pieces of data. Through time series modelling, the advantages of and changes in heritage declarations in different regions and periods were analysed, and the impact of heritage strategy on the number of heritage sites included in each region was evaluated. The results showed that the implementation of heritage policy greatly impacted each region, especially on the number of heritage sites in Asia and the Pacific region. Using the heritage era to carry out modelling analysis, from the perspective of the integrity of historical heritage cultural types, it is considered that there may be cultural heritage sites in the Caribbean and Latin America that have not been given enough attention. The modelling analysis results of era attributes can support the fairness of heritage determination. By calculating the frequency and peak value of heritage sites at the national scale, the frequency and peak value of each country in the top 10 list are used to characterize the ability of national declarations of cultural heritage and reveal the differences in the ability of each member country to declare heritage sites and the heritage era. By calculating the distribution density of the heritage era, this study finds that the world’s cultural heritage is not concentrated in the Middle Ages (600–1450) but the periods of Reformation and Exploration (1450–1700) and Progress and Empire (1850–1914). The above analysis shows that there are imbalances and strategic adjustment effects concerning regions, countries, eras and types in World Heritage list development. The composition types of heritage are complex, and the combination types have obvious changes in different periods. It is suggested that the strategy of world cultural heritage collection should be further optimized to fully guarantee the balance of regions, countries and types, and the heritage value should be fully considered in heritage protection with more diversity and complexity of types.

scholarly journals Efficient symbolic computation of approximated small-signal characteristics of analog integrated circuits

1995 ◽  
Vol 30 (3) ◽  
pp. 327-330 ◽  
Author(s):  
P. Wambacq ◽  
F.V. Fernandez ◽  
G. Gielen ◽  
W. Sansen ◽  
A. Rodriguez-Vazquez
Keyword(s):  
Integrated Circuits ◽  
Symbolic Computation ◽  
Analog Integrated Circuits ◽  
Small Signal ◽  
Signal Characteristics
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