Temperature transient effect on the large-signal properties and frequency chirping in pulsed silicon DDR IMPATTs at 94 GHz
01 Dec 2012-pp 1-3
TL;DR: In this article, the effect of temperature transient on the large-signal properties and frequency chirping of 94 GHz pulsed silicon Double-Drift Region (DDR) Impact Avalanche Transit Time (IMPATT) device is investigated.
Abstract: In this paper the effect of temperature transient on the large-signal properties and frequency chirping of 94 GHz pulsed silicon Double-Drift Region (DDR) Impact Avalanche Transit Time (IMPATT) device is investigated. A transient thermal model and a large-signal simulation method based on non-sinusoidal voltage excitation have been developed by the authors' to study the effect temperature transients on the large-signal characteristics and frequency chirping in pulsed Si DDR IMPATTs. Results show that the device is capable of delivering a peak pulsed power output of 17.5 W with 12.8% efficiency when the voltage modulation is 60%. The maximum junction temperature rise is 350.2 K for a peak pulsed bias current of 6.79 A with 100 ns pulsewidth and 0.5 percent duty cycle; whereas the chirp bandwidth is 8.3 GHz.
Citations
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TL;DR: In this paper, a large-signal simulation model based on non-sinusoidal voltage excitation is used to study the influence of skin depth on the parasitic series resistance of millimeter-wave IMPATT devices based on Silicon.
Abstract: An attempt is made in this paper to study the influence of skin depth on the parasitic series resistance of millimeter-wave IMPATT devices based on Silicon. The method is based on the concept of depletion width modulation of the device under large-signal condition. A large-signal simulation model based on non-sinusoidal voltage excitation is used for this study. The electric field snap-shots of 35 GHz Single-Drift Region (SDR) and 94 GHz Double-Drift Region (DDR) IMPATT devices are first obtained from which the series resistances are estimated by incorporating the effect of skin depth in the modeling and simulation. The series resistances of these devices are also obtained by neglecting the effect of skin depth. The values of series resistances obtained from the simulation are compared with the corresponding experimentally reported values. It is observed that the series resistance estimated by including the skin effect is in closer agreement with the experimental values as compared to that without including the same. Thus the skin effect plays an important role for determining the series resistance of IMPATT devices at millimeter-wave frequency bands.
36 citations
TL;DR: In this paper, a large-signal model and a simulation technique based on non-sinusoidal voltage excitation are used to obtain the electric field snapshots from which the series resistance and related high-frequency properties of a 35 GHz SDR Impact Avalanche Transit Time (IMPATT) device have been estimated for different bias current densities.
Abstract: A large-signal model and a simulation technique based on non-sinusoidal voltage excitation are used to obtain the electric field snapshots from which the series resistance and related high-frequency properties of a 35 GHz Silicon Single-Drift Region (SDR) Impact Avalanche Transit Time (IMPATT) device have been estimated for different bias current densities. A novel method is proposed in this paper to determine the parasitic series resistance of a millimeter-wave IMPATT device from large-signal electric field snapshots at different phase angles of a full cycle of steady-state oscillation. The method is based on the depletion width modulation of the device under a large-signal condition. The series resistance of the device is also obtained from the large-signal admittance characteristics at threshold frequency. The values of series resistance of a 35 GHz SDR IMPATT diode obtained from the proposed method and the large-signal admittance method are compared with experimentally reported values. The results show that the proposed method provides better and closer agreement with the experimental value.
25 citations
01 Jun 2013
TL;DR: In this paper, a large-signal simulation is carried out to investigate the performance of Double-Drift Region (DDR) Impact Avalanche Transit Time (IMPATT) device based on semiconducting type-IIb diamond as millimeter-wave source operating at 94 GHz atmospheric window frequency.
Abstract: Large-signal simulation is carried out in this paper to investigate the prospects and potentiality of Double-Drift Region (DDR) Impact Avalanche Transit Time (IMPATT) device based on semiconducting type-IIb diamond as millimeter-wave source operating at 94 GHz atmospheric window frequency. Large-signal simulation method developed by the authors and presented in this paper is based on non-sinusoidal voltage excitation. The simulation is carried out to obtain the large-signal characteristics such as RF power output, DC to RF conversion efficiency etc. of DDR diamond IMPATT device designed to operate at 94 GHz. The results show that the device is capable of delivering a peak RF power output of 7.01 W with 10.18% DC to RF conversion efficiency for a bias current density of 6.0×10 Am and voltage modulation of 60% at 94 GHz; whereas for the same voltage modulation 94 GHz DDR Si IMPATT can deliver only 693.82 mW RF power with 8.74 efficiency for the bias current density of 3.4×10 Am.
9 citations
01 Jan 2022
TL;DR: A short review on impact avalanche transit time (IMPATT) sources for the generation of terahertz (THz) waves has been presented in this paper, where the noise outputs of the sources at different electromagnetic spectrum have been discussed.
Abstract: A short review on avalanche transit time devices has been presented in this chapter. From its first proposal till the state of the art, impact avalanche transit time (IMPATT) sources for the generation of terahertz (THz) waves have been briefly described. The noise outputs of the sources at different electromagnetic spectrum have been discussed. The details of deferent device structures, potential materials, popular simulation techniques, etc. are also appended in this chapter.
References
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TL;DR: In this paper, the power output and efficiency of a Read-type IMPATT diode was analyzed using a closed-form solution of the nonlinear equations describing a Read type diode.
Abstract: This paper presents results on RF power output and efficiency of IMPATT oscillators obtained from a large-signal model of these devices. The results are obtained from a closed-form solution of the nonlinear equations describing a Read-type IMPATT diode. The closed-form solution is obtained by assuming a short transit time through the drift region compared to the RF period. The solution is used to obtain the large-signal diode impedance. The analysis shows that the power output of an IMPATT diode depends strongly on the series load resistance presented to the active part of the diode and that the change in diode reactance with increasing bias current also depends on the series resistance. Plots of power output as a function of frequency, bias current, and load resistance are presented. Frequency tuning of the oscillator through current variation is also discussed. Experimental results are presented and compared with the theoretical ones wherever possible. The results lead to an improved understanding of such oscillators and are extremely useful in optimizing their performance and determining their limitations.
52 citations
Additional excerpts
...Large-signal analysis of IMPATT devices provides several important properties of IMPATT oscillators such as dependence of RF power output, DC to RF conversion efficiency and frequency tuning of the oscillators on the device parameters, bias current and RF circuitry etc [1]....
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TL;DR: In this paper, a model for computing the thermal transient response of a diamond-heat-sinked IMPATT diode has been formulated as a means for accurately predicting the degree of heating or cooling of the junction when the diode is pulsed into or out of avalanche.
Abstract: A model for computing the thermal transient response of a diamond-heat-sinked IMPATT diode has been formulated as a means for accurately predicting the degree of heating or cooling of the junction when the diode is pulsed into or out of avalanche. The model consists of an electrical network analog for the heat conduction process, and the transient analysis of this network has been performed using the IBM Advanced Statistical Analysis Program (ASTAP). Also incorporated into the model are the results of previous numerical determinations of steady-state temperature distributions in IMPATT diamond heat sinks. The thermal responses for diode turnon and turnoff and for power surges have been found for several different designs of IMPATT diodes, both Si and GaAs. Turnon transients calculated with this model have been compared with transients calculated by a published method [11] involving a transcendental equation. The two models were roughly in agreement. However, because the previously published method neglects the heat flow path through the chip, it yielded lower values than the network analog model described here for the junction temperature in the first few microseconds after turnon of the diode. The results of these calculations showed that the transient response varied depending on the size of the chip and that significant temperature changes occurred in time intervals ranging from less than 0.1 µs to several microseconds for practical diodes. The results also showed that a description of the transient response in terms of a simple time constant is not meaningful, because the early response does not approximate an exponential curve. To provide a means for making quite accurate desk calculations of diode thermal transients, two approximations have been derived which can be used without computer programs.
19 citations
"Temperature transient effect on the..." refers methods in this paper
...After evaluating the junction temperature from the thermal analysis [2], the material parameters of Si corresponding to that temperature have been incorporated into the large-signal simulation program developed by the authors to find out the large-signal power and efficiency....
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01 Jan 1979
TL;DR: In this article, a double-drift IMPATT diodes were used for W-band high peak power oscillators with a peak power of 13.5W with a 0.5 percent duty cycle.
Abstract: High peak power oscillators using double-drift IMPATT diodes have been developed in W-band, The diodes were operated with 100 ns pulsewidth and 0.5 percent duty cycle. Peak power of 13 watts were consistently achieved. As a best result, over 15W peak power was achieved with selected diodes.
10 citations
"Temperature transient effect on the..." refers background or result in this paper
...These results are in close agreement with experimental reports for pulsed Si DDR IMPATT source [4]....
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...1310×10 m corresponding to the circular cross-section of the device (junction diameter, Dj = 120 m) [4]....
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