This Thesis is a contribution for dimensioning aspects of circuits designs in superconductor ele... more This Thesis is a contribution for dimensioning aspects of circuits designs in superconductor electronics. Mainly superconductor comparators inclusive Josephson comparators as well as QOJS-Comparators are investigated. Both types were investigated in terms of speed and sensitivity. The influence of the thermal noise on the decision process of the comparators represent in so called gray zone, which is analysed in this thesis. Thereby, different relations between design parameters were derived. A circuit model of the Josephson comparator was verified by experiments. Concepts of superconductor analog-to-digital converters, which are based on above called comparators, were investigated in detail. From the comparator design rules, new rules for AD-converters were derived. Because of the reduced switching energy, the signal to noise ratio (SNR) of the circuits is affected and therefore the reliability of the decision-process is affected. For special applications with very demanding requir...
Au debut de l’annee 2013, l’economie auvergnate affiche quelques signes positifs. L’emploi salari... more Au debut de l’annee 2013, l’economie auvergnate affiche quelques signes positifs. L’emploi salarie marchand progresse dans l’ensemble des secteurs, hormis l’industrie. Toutefois, les effectifs industriels se sont stabilises apres une baisse en fin d’annee precedente. Cette dynamique de l’emploi ne se retrouve pas a l’echelon national ou seul l’interim progresse. L’augmentation du nombre de logements mis en chantier et le dynamisme de l'activite touristique sont d'autres signes encourageants pour l'economie regionale. Cependant, le marche du travail continue a se degrader.
IEEE Transactions on Applied Superconductivity, 2015
The Josephson comparator is one of the building blocks of superconductor electronics. It is used ... more The Josephson comparator is one of the building blocks of superconductor electronics. It is used as a decision element in all analog and digital circuits. For fast high-bandwidth analog-to-digital converters as well as for digital circuits with reduced switching energy its high sensitivity is most important. Thermal noise limits its decision uncertainty. In this work we analyze the influence of the bias current on the gray zone of a Josephson comparator. Circuit simulations are compared against experimental data. The experimental analysis shows a characteristic dependence of the gray zone on the bias current. We can identify a clear minimum value. This point is related to a certain clock frequency. At low frequencies the simulated relationship between the gray zone and the bias current is in very good agreement with experimental results. The comparison confirmed the circuit model and enables to adjust the design to certain applications to realize the best trade-off between clock frequency and grey zone. The article describes the experimental validation procedure and a derived normalized dependency in detail.
The Josephson comparator is one of the fundamental building blocks of rapid single flux quantum (... more The Josephson comparator is one of the fundamental building blocks of rapid single flux quantum (RSFQ) electronics. Within this circuit family it is the exclusive device which provides logical data processing. The Josephson comparator is also the basic decision element for very fast analog-to-digital converters and sampler circuits for low input power and high-bandwidth signals based on the RSFQ technique.
This Thesis is a contribution for dimensioning aspects of circuits designs in superconductor ele... more This Thesis is a contribution for dimensioning aspects of circuits designs in superconductor electronics. Mainly superconductor comparators inclusive Josephson comparators as well as QOJS-Comparators are investigated. Both types were investigated in terms of speed and sensitivity. The influence of the thermal noise on the decision process of the comparators represent in so called gray zone, which is analysed in this thesis. Thereby, different relations between design parameters were derived. A circuit model of the Josephson comparator was verified by experiments. Concepts of superconductor analog-to-digital converters, which are based on above called comparators, were investigated in detail. From the comparator design rules, new rules for AD-converters were derived. Because of the reduced switching energy, the signal to noise ratio (SNR) of the circuits is affected and therefore the reliability of the decision-process is affected. For special applications with very demanding requir...
Au debut de l’annee 2013, l’economie auvergnate affiche quelques signes positifs. L’emploi salari... more Au debut de l’annee 2013, l’economie auvergnate affiche quelques signes positifs. L’emploi salarie marchand progresse dans l’ensemble des secteurs, hormis l’industrie. Toutefois, les effectifs industriels se sont stabilises apres une baisse en fin d’annee precedente. Cette dynamique de l’emploi ne se retrouve pas a l’echelon national ou seul l’interim progresse. L’augmentation du nombre de logements mis en chantier et le dynamisme de l'activite touristique sont d'autres signes encourageants pour l'economie regionale. Cependant, le marche du travail continue a se degrader.
IEEE Transactions on Applied Superconductivity, 2015
The Josephson comparator is one of the building blocks of superconductor electronics. It is used ... more The Josephson comparator is one of the building blocks of superconductor electronics. It is used as a decision element in all analog and digital circuits. For fast high-bandwidth analog-to-digital converters as well as for digital circuits with reduced switching energy its high sensitivity is most important. Thermal noise limits its decision uncertainty. In this work we analyze the influence of the bias current on the gray zone of a Josephson comparator. Circuit simulations are compared against experimental data. The experimental analysis shows a characteristic dependence of the gray zone on the bias current. We can identify a clear minimum value. This point is related to a certain clock frequency. At low frequencies the simulated relationship between the gray zone and the bias current is in very good agreement with experimental results. The comparison confirmed the circuit model and enables to adjust the design to certain applications to realize the best trade-off between clock frequency and grey zone. The article describes the experimental validation procedure and a derived normalized dependency in detail.
The Josephson comparator is one of the fundamental building blocks of rapid single flux quantum (... more The Josephson comparator is one of the fundamental building blocks of rapid single flux quantum (RSFQ) electronics. Within this circuit family it is the exclusive device which provides logical data processing. The Josephson comparator is also the basic decision element for very fast analog-to-digital converters and sampler circuits for low input power and high-bandwidth signals based on the RSFQ technique.
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Papers by Taghrid Haddad