In this paper, the influence of tunnelling on the RF performance of millimetre-wave (mm-wave) impact ionisation avalanche transit time (IMPATT) diodes operating in mixed tunnelling and avalanche transit time mode is studied by taking into account the parasitic series resistance of the device. The results show that the parasitic resistance of mm-wave IMPATTs increases and consequently the power delivered by the device decreases due to the consequence of band-to-band tunnelling. The critical background doping concentration and operating frequency are found to be 5.0 × 1023 m-3 and 260 GHz, respectively, above which the influence of tunnelling on the RF performance of the device becomes predominant. © 2014 © 2014 Taylor & Francis.

A ACHARYYA

M MUKHERJEE

J P BANERJEE

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

&nbsp;

The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

&nbsp;

It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Effects of tunnelling current on millimetre-wave IMPATT devices

International Journal of Electronics

The authors have developed a quantum corrected drift-diffusion model for impact avalanche transit time (IMPATT) devices by coupling the density gradient model with the classical drift-diffusion model. A large-signal simulation technique has been developed by incorporating the quantum potentials in the current density equations for the analysis of double-drift region IMPATT devices based on different semiconductors such as Wurtzite–GaN, InP, type-IIb diamond (C), 4H–SiC and Si deigned to operate at different millimeter-wave (mm-wave) and terahertz (THz) frequencies. It is observed that, the RF power output and DC to RF conversion efficiency of the devices operating at higher mm-wave ($$>$$>140 GHz) and THz frequencies reduce due to the incorporation of quantum corrections in the model; but the effect of quantum corrections are negligible for the devices operating at lower mm-wave frequencies ($$\le $$≤140 GHz). © 2014, Springer Science+Business Media New York.

Journal of Computational Electronics

Quantum corrected drift-diffusion model for terahertz IMPATTs based on different semiconductors

An attempt is made in this paper to explore the potentiality of semiconducting type-IIb diamond as the base material of double-drift region (DDR) impact avalanche transit time (IMPATT) devices operating at both millimetre-wave (mm-wave) and terahertz (THz) frequencies. A rigorous large-signal (L-S) simulation based on the non-sinusoidal voltage excitation (NSVE) model developed earlier by the authors is used in this study. At first, a simulation study based on avalanche response time reveals that the upper cut-off frequency for DDR diamond IMPATTs is 1.5 THz, while the same for conventional DDR Si IMPATTs is much smaller, i.e. 0.5 THz. The L-S simulation results show that the DDR diamond IMPATT device delivers a peak RF power of 7.79 W with an 18.17% conversion efficiency at 94 GHz; while at 1.5 THz, the peak power output and conversion efficiency decrease to 6.19 mW and 8.17% respectively, taking 50% voltage modulation. A comparative study of DDR IMPATTs based on diamond and Si shows that the former excels over the later as regards high frequency and high power performance at both mm-wave and THz frequency bands. The effect of band to band tunneling on the L-S properties of DDR diamond and Si IMPATTs has also been studied at different mm-wave and THz frequencies. © 2014 Chinese Institute of Electronics.

Journal of Semiconductors

Potentiality of semiconducting diamond as the base material of millimeter-wave and terahertz IMPATT devices

Quantum correction is necessary on the classical drift-diffusion (CLDD) model to predict the accurate behavior of high frequency performance of ATT devices at frequencies greater than 200 GHz when the active layer of the device shrinks in the range of 150-350 nm. In the present work, a quantum drift-diffusion model for impact avalanche transit time (IMPATT) devices has been developed by incorporating appropriate quantum mechanical corrections based on density-gradient theory which macroscopically takes into account important quantum mechanical effects such as quantum confinement, quantum tunneling, etc. into the CLDD model. Quantum potentials (synonymous as Bohm potentials) have been incorporated in the current density equations as necessary quantum mechanical corrections for the analysis of millimeter-wave (mm-wave) and Terahertz (THz) IMPATT devices. It is observed that the large-signal (L-S) performance of the device is degraded due to the incorporation of quantum corrections into the model when the frequency of operation increases above 200 GHz; while the effect of quantum corrections are negligible for the devices operating at lower mm-wave frequencies. © 2014 Springer Science+Business Media New York.

Quantum drift-diffusion model for IMPATT devices

Noise performance of different structures of Si Si1-x Ge x anisotype heterojunction double-drift region (DDR) mixed tunneling and avalanche transit time (MITATT) devices has been studied. The devices are designed for operation at millimeter-wave W-band frequencies. A simulation model has been developed to study the noise spectral density and noise measure of the device. Two different mole fractions x = 0.1 and x = 0.3 of Ge and corresponding four types of device structure are considered for the simulation. The results show that the n - Si 0.7 Ge 0.3 P -Si heterojunction DDR structure of MITATT device excels all other structures as regards noise spectral density (0.82 × 10 - 16 V 2 sec) and noise measure (33.09 dB) as well as millimeter-wave properties such as DC-to-RF conversion efficiency (20.15%) and CW power output (773.29 mW). © 2013 Suranjana Banerjee et al.

Fulltext

Active and Passive Electronic Components

Noise performance of heterojunction DDR MITATT devices based on Si âˆ¼ Si1-x Gex at W-Band

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. © 2012, The Author(s).

Applied Nanoscience (Switzerland)

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

Potentiality of Impact Avalanche Transit Time (IMPATT) devices based on different semiconductor materials such as InP, 4H-SiC, and Wurtzite-GaN (Wz-GaN) has been explored for operation at terahertz (THz) frequencies. Drift-diffusion model is used to design double-drift region (DDR) IMPATTs based on above mentioned materials at different millimeter-wave (mm-wave) and THz frequencies and the upper cut-off frequency limits of those devices are obtained from the avalanche response times at those mm-wave and THz frequencies. Results show that the upper cut-off frequency limits of both InP and 4H-SiC DDR IMPATTs are 1.0 THz; whereas, the same is 5.0 THz in Wz-GaN DDR IMPATTs. The Wz-GaN DDR IMPATTs emerge as the most suitable devices for generation of THz frequencies due to their small avalanche response time, high DC to RF conversion ratio, and sufficiently high RF power output at THz frequencies. But, it is observed that up to 1.0 THz, 4H-SiC DDR IMPATTs excel Wz-GaN DDR IMPATTs due to their higher output power densities. 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. Copyright © 2013 by the IETE.

IETE Journal of Research

Potentiality of IMPATT devices as terahertz source: An avalanche response time-based approach to determine the upper cut-off frequency limits

Extensive simulation experiments have been carried out on the DC and high-frequency characteristics of α-(4H) Silicon Carbide based double-drift (p++ p n n++ type) impact avalanche transit time (IMPATT) diodes at two important millimeterwave window frequencies (35 and 140 GHz). The studies reveal that the IMPATT diode designed at Ka-band (at around 35.0 GHz) may yield an RF power density of 10.72 × 1012 Wm-2 with an efficiency of 21.5%, whereas the D-band (at around 140.0 GHz) IMPATT is capable of delivering an RF power density of 0.38 × 1012 Wm-2 with an efficiency of 15.0%. These results are very encouraging to choose SiC as a suitable base material for developing high-power and high-frequency IMPATT diodes. Impurity charge spikes are introduced in the flatly doped n and p regions of the double-drift diodes in the form of single low-high-low (p++ p p+ p n n+ n n++ type) bump. The effects of this charge bump on the mm-wave characteristics of the double-drift 4H-SiC IMPATTs are analyzed for the first time, through a modified simulation technique. It is interesting to note that the introduction of charge spikes improves the overall performance of the designed diodes at the window frequencies. © 2009 by the IETE.

Effects of charge bump on high-frequency characteristics of Î±-SiC-based double-drift ATT diodes at millimeter-wave window frequencies

Computer simulation of the high frequency properties of flat profile double drift region (DDR) impatts based on indium phosphide is carried out for mm‐wave V‐band (≈ 60 GHz) frequency. The profiles of negative resistance in the depletion layer of the DDR diode and their admittance characteristics are analysed for three current levels. The results show that the total negative resistance which is an useful parameter to indicate the output power from the device does not degrade appreciably due to mobile space charge even if a high current viz. 3 × 108 Am−2 is pushed through these devices. Copyright © 1988 WILEY‐VCH Verlag GmbH &amp; Co. KGaA

Journal	Data powered by TypesetInternational Journal of Electronics
Publisher	Data powered by TypesetTaylor and Francis Ltd.
ISSN	0020-7217