| 1. |
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| 2. |
- Joffrin, E., et al.
(författare)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 3. |
- Murari, A., et al.
(författare)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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| 4. |
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| 5. |
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| 6. |
- Meyer, E., et al.
(författare)
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The state of the art in beyond 5G distributed massive multiple-input multiple-output communication system solutions
- 2022
-
Ingår i: Open Research Europe. - : F1000 Research Ltd. - 2732-5121. ; 2
-
Forskningsöversikt (refereegranskat)abstract
- Beyond fifth generation (5G) communication systems aim towards data rates in the tera bits per second range, with improved and flexible coverage options, introducing many new technological challenges in the fields of network architecture, signal pro- cessing, and radio frequency front-ends. One option is to move towards cell-free, or distributed massive Multiple-Input Multiple-Output (MIMO) network architectures and highly integrated front-end solutions. This paper presents an outlook on be- yond 5G distributed massive MIMO communication systems, the signal processing, characterisation and simulation challenges, and an overview of the state of the art in millimetre wave antennas and electronics.
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| 7. |
- Carlsson, Emelie, et al.
(författare)
-
A real-estate price index for Stockholm, 1726–1875
- 2022
-
Ingår i: Banking, Bonds, National Wealth, and Stockholm House Prices, 1420–2020. - Stockholm : Ekerlids förlag. - 9789189323605 ; , s. 297-334
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter presents new, nominal and real price indices for real estate in Stockholm from 1726 up to 1875. The new series presented here can be linked to already existing price indices for real estate in Stockholm: from 1875 up to 1957; from 1957 to1975 3 and; from 1975 up to 2020.For this, a new database is used that covers registered real estate transactions in the present inner city of Stockholm for the period and the method of repeated sales is applied. The indices are based on information from 22,169 unique transactions. To control for qualitative changes inthe housing stock, a database of 7,915 issued building permits has been used.
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| 8. |
- Enjin, Anders, et al.
(författare)
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Developmental disruption of recurrent inhibitory feedback results in compensatory adaptation in the Renshaw cell-motor neuron circuit
- 2017
-
Ingår i: Journal of Neuroscience. - 0270-6474 .- 1529-2401. ; 37:23, s. 5634-5647
-
Tidskriftsartikel (refereegranskat)abstract
- When activating muscles, motor neurons in the spinal cord also activate Renshaw cells, which provide recurrent inhibitory feedback to the motor neurons. The tight coupling with motor neurons suggests that Renshaw cells have an integral role in movement, a role that is yet to be elucidated. Here we used the selective expression of the nicotinic cholinergic receptor α2 (Chrna2) in mice to genetically target the vesicular inhibitory amino acid transporter (VIAAT) in Renshaw cells. Loss of VIAAT from Chrna2Cre-expressing Renshaw cells did not impact any aspect of drug-induced fictive locomotion in the neonatal mouse or change gait, motor coordination, or grip strength in adult mice of both sexes. However, motor neurons from neonatal mice lacking VIAAT in Renshaw cells received spontaneous inhibitory synaptic input with a reduced frequency, showed lower input resistance, and had an increased number of proprioceptive glutamatergic and calbindin-labeled putative Renshaw cell synapses on their soma and proximal dendrites. Concomitantly, Renshaw cells developed with increased excitability and a normal number of cholinergic motor neuron synapses, indicating a compensatory mechanism within the recurrent inhibitory feedback circuit. Our data suggest an integral role for Renshaw cell signaling in shaping the excitability and synaptic input to motor neurons.
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| 9. |
- Eriksson, Klas A. M., 1983-
(författare)
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How the City was Owned : Property Markets, Property Rights, and Entrepreneurship in Stockholm, Sweden 1726-2018
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this dissertation three central themes concerning the ownership and allocation in the city of Stockholm over long periods are examined.The first theme property markets involves constructions of real estate price indexes spanning from 1726 to 2018. The second theme property rights concerns the regulation of private and public ownership of real estate from 1874 to 2010. The third theme entrepreneurship in urban environments is an examination of the efforts to influence property markets and property rights through entrepreneurship in difference sectors from the 1920s to the 2010s.With an extensive amount of empirical material, this dissertation examines and relates the three themes to each other and shed new light on urban dynamics from an historical perspective. This dissertation is particularly important today when ownership and prices of real estate in cities are burning issues, and entrepreneurship is of central importance for development. The dissertation is a compilation thesis consisting of six articles.
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| 10. |
- Eriksson, Klas, 1983, et al.
(författare)
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Design and Characterization of H-Band (220-325 GHz) Amplifiers in a 250-nm InP DHBT Technology
- 2014
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Ingår i: IEEE Transactions on Terahertz Science and Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 2156-342X .- 2156-3446. ; 4:1, s. 56-64
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Tidskriftsartikel (refereegranskat)abstract
- Design and characterization of InP DHBT amplifiers in common-emitter and common-base topologies are presented. Both one-stage and multistage circuits are demonstrated. For one of the amplifiers, a peak gain of 24 dB at 255 GHz is measured, which is among the highest reported gains for HBT amplifiers above 200 GHz, and more than 10 dB gain at 210-315 GHz. The noise figure of this amplifier is measured on-wafer at 240-295 GHz, and it demonstrates a minimum noise figure of 10.4 dB at 265 GHz, which is the lowest reported noise figure for HBT amplifiers above 200 GHz.
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| 11. |
- Eriksson, Klas, 1983, et al.
(författare)
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H-band MMIC amplifiers in 250 nm InP DHBT
- 2012
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Ingår i: 19th International Conference on Microwaves, Radar and Wireless Communications, MIKON 2012, Warsaw, 21-23 May 2012. - 9781457714351 ; 2, s. 744-747
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Konferensbidrag (refereegranskat)abstract
- In this paper, single-stage and multistage amplifiers of two different topologies, common-base with resistive feedback and common-emitter, operating at up to 290 GHz are presented and demonstrated. The amplifiers use an indium-phosphide (InP) double-heterojunction bipolar transistor (DHBT) process. The multistage common-emitter amplifier demonstrates a gain above 10 dB from 220 to 280 GHz with a peak gain of 15 dB while the multistage common-base amplifier demonstrates a gain of 16 dB at 265 GHz.
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| 12. |
- Eriksson, Klas, 1983, et al.
(författare)
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InP DHBT Amplifier Modules Operating Between 150 and 300 GHz Using Membrane Technology
- 2015
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 63:2, s. 433-440
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present WR05 (140-220 GHz) and WR03 (220-325 GHz) five-stage amplifier modules with novel membrane microstrip-to-waveguide transitions. The modules use a 250-nm InP double heterojunction bipolar transistor (DHBT) technology and multilayer thin-film microstrip transmission lines. The waveguide transitions use E-plane probes on 3- μm-thin GaAs membrane substrate. Beam lead connectors integrated on the transition eliminate the need of highly reactive bond wires. In addition, process steps such as backside metallization, backside vias, and nonrectangular dicing of the integrated circuits (ICs) are not required. The WR05 amplifier module demonstrates a peak gain of 24 dB at 245 GHz and more than 10-dB gain from 155 to 270 GHz. The WR-03 module has 19-dB gain from 230 to 254 GHz with input and output return loss better than 10 dB from 225 to 330 GHz. The two modules were also characterized in terms of noise. The minimum noise figures were measured to 9.7 dB at 195 GHz and 10.8 dB at 240 GHz for the WR05 and WR03 modules, respectively. To the authors' best knowledge, these are the first published results on an InP DHBT amplifier modules operating at these high frequencies. It is also the first time that membrane technology is used for IC packaging, regardless of IC technology.
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| 13. |
- Eriksson, Klas, 1983
(författare)
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InP DHBT Amplifiers and Circuit Packaging up to Submillimeter-Wave Frequencies
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis treats the design and characterization of amplifiers operating up tosubmillimeter-wave frequencies and packaging of such circuits into waveguidemodules. The circuits use an advanced indium phosphide (InP) double heterojunctionbipolar transistor (DHBT) process with a multilayer back-end. Several amplifiers inthe frequency range from 80 to 300 GHz with state-of-the-art performance arepresented. The amplifiers utilize different transistor configurations: common-emitter,common-base, and cascode. One of the amplifiers, a five-stage common-emittercircuit, demonstrates 24 dB gain at 255 GHz with a minimum noise figure of 10.4 dBat 265 GHz. This is the lowest reported noise figure for amplifiers in bipolartechnology operating at such high frequencies. Circuits like these can findapplications in a variety of systems such as wireless high data-rate communicationlinks and high-resolution imaging systems.Furthermore, amplifiers with the highest reported bandwidths for transistorbasedamplifiers, regardless of transistor technology, are presented in this thesis.These amplifiers use distributed topologies to achieve such wideband characteristics.The widest bandwidth is reached with a 2-cascaded distributed amplifier that has anaverage gain of 16 dB from 2 to 237 GHz, i.e., a bandwidth of 235 GHz.A potential problem with integrated circuits with a large front-side metallizationis the risk of resonating parasitic modes within the circuit substrate. The influence ofsuch resonances is studied through simulations and measurements of passive andactive circuits. It is shown that a resistive Si carrier underneath the circuit is aneffective method to eliminate the effects of parasitic substrate modes.The high operating frequencies of these circuits make the development of afunctional packaging method challenging. In this thesis, two waveguide InP DHBTamplifier modules operating in the frequency bands 150‒260 GHz and 210‒300 GHzusing a novel waveguide-to-circuit transition realized in membrane technology aredemonstrated. It is the first published results on InP DHBT amplifier modulesoperating at these high frequencies. Furthermore, membrane technology has not beenused in packaging of transistor-based integrated circuits before. One of the amplifiermodules is measured at a temperature of 100 K. The noise temperature of the moduleis reduced from 3500 K at room temperature to 1800 K when cooled. This is the firstreported characterization of an InP DHBT circuit at cryogenic temperature.
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| 14. |
- Eriksson, Klas, 1983, et al.
(författare)
-
InP DHBT Distributed Amplifiers With Up to 235-GHz Bandwidth
- 2015
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 63:4, s. 1334-1341
-
Tidskriftsartikel (refereegranskat)abstract
- Three wideband amplifiers in double-heterojunction bipolar transistor technology have been designed and measured. The amplifiers use different types of distributed amplifier (DA) topologies, all based on cascode gain cells. A single-stage DA design achieves 7.5-dB gain and 192-GHz bandwidth and a two-cascaded single-stage DA achieves an average gain of 16 dB with a bandwidth of 235 GHz. The third circuit is a conventional DA with more than 10-dB gain from 70 kHz up to 180 GHz. To the authors' best knowledge, the single-stage DA and the two-cascaded single-stage DA are the widest band amplifiers in any technology reported to date. Furthermore, the conventional DA has a record bandwidth for circuits in conventional DA topology with gain from near dc.
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| 15. |
- Eriksson, Klas, 1983, et al.
(författare)
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InP DHBT wideband amplifiers with up to 235 GHz bandwidth
- 2014
-
Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781479938698 ; , s. Art. no. 6848436-
-
Konferensbidrag (refereegranskat)abstract
- Two wideband amplifier MMICs are designed and tested. Both designs employ InP double-heterojunction bipolar transistor technology. The amplifiers are designed using cascode cells, in a distributed amplifier topology, with simple on-chip resistive bias circuitry. A single stage design achieves 7.5 dB gain and 192 GHz bandwidth and a 2-cascaded distributed amplifier achieves gain in excess of 16 dB and with bandwidth exceeding 235 GHz, thus being the widest band amplifiers reported to date.
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| 16. |
- Eriksson, Klas, 1983, et al.
(författare)
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Suppression of Parasitic Substrate Modes in Multilayer Integrated Circuits
- 2015
-
Ingår i: IEEE Transactions on Electromagnetic Compatibility. - 0018-9375 .- 1558-187X. ; 57:3, s. 591-594
-
Tidskriftsartikel (refereegranskat)abstract
- Integrated circuits (ICs) with multilayer backend process and a large front-side ground plane support the propagation of parasitic substrate modes. These modes resonate at frequencies that typically are within the bandwidth of circuits operating close to and in the submillimeter-wave range, i.e., beyond 300 GHz. The resonances cause unwanted coupling and feedback, which result in circuit instability and degraded performance for circuits operating in the range of these resonances. A common method to suppress these modes from propagating is to use numerous through-wafer vias distributed over the entire circuit. In this letter, we present a study of substrate modes in multilayer ICs with thin-film microstrip interconnects at 125-330 GHz. We show that a doped Si carrier underneath the circuit effectively eliminates the effect of substrate modes on the circuit functionality. This method requires no backside processed through-wafer vias and no backside metallization.
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| 17. |
- Giannakopoulos, Stavros, 1989, et al.
(författare)
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Ultra-broadband common collector-cascode 4-cell distributed amplifier in 250nm InP HBT technology with over 200 GHz bandwidth
- 2017
-
Ingår i: Microwave Integrated Circuits Conference (EuMIC), 2017 12th European. - 9782874870484 ; 2017-January
-
Konferensbidrag (refereegranskat)abstract
- An ultra broadband MMIC amplifier is designed using InP double-heterojunction bipolar transistors and its on-chip measurements are reported. The multi-cell distributed amplifier uses four gain cells where each consists of a common collector input stage followed by a cascode gain stage. The chip includes bias, decoupling and terminating circuits for the dc and RF interconnects; it measures 0.72 mm by 0.4 mm. It consumes 210 mW of power and can deliver up to 5.5 dBm of output power at 195 GHz. The amplifier achieves an average gain of 13.5 dB with an overall bandwidth over 200 GHz and a ± 2 dB gain ripple. The measurements indicate that this is the widest band dc-coupled amplifier reported to date and has the highest bandwidth reported among non-cascaded distributed amplifiers.
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| 18. |
- Lai, Szhau, 1985, et al.
(författare)
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A varactor model including valanche noise source for VCOs phase noise simulation
- 2011
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Ingår i: 41th European Microwave Conference , Manchester, UK, Oct 10-13, 2011. - 9781612842356 ; , s. 591-594
-
Konferensbidrag (refereegranskat)abstract
- Abstract — This work studies an important area of oscillatoroperation – VCO biased at varactor breakdown. In this operation, the oscillator’s phase noise is primarily determined by avalanche noise generated in the varactor, i.e., the phase noise can be modulated by the incremental shot noise generated at varactor breakdown. A simple experimental diode model was optimized for modeling varactor-breakdown current and an empirical shot noise model based on Hine’s theory presents good agreement with noise power measurements of varactors.The developed varactor noise-model has successfully been used to simulate the phase noise of a single-ended Colpitts InGaP HBT VCO over and beyond the varactor’s breakdown voltage. The VCO presents a phase noise below -100dBc/Hz for varactor voltages lower than breakdown voltage. Beyond the breakdown the phase noise gradually increases to -60 dBc/Hz@100kHz with a centre frequency deviating less than 0.6% from a 7.38GHz carrier.
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| 19. |
- Li, Y., et al.
(författare)
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D-band SiGe transceiver modules based on silicon-micromachined integration
- 2019
-
Ingår i: Asia-Pacific Microwave Conference Proceedings, APMC. - : Institute of Electrical and Electronics Engineers (IEEE). ; 2019-December, s. 883-885
-
Konferensbidrag (refereegranskat)abstract
- This paper reports on 130 GHz transceiver modules consisting of integrated multi-functional chipsets in a commercial 130nm SiGe BiCMOS process. The interconnect between the chipset and the package is non-galvanic and is realized in silicon micromachining technique. After successful fabrication and assembly, the individual Tx and Rx modules as well as the combined Tx-Rx link were tested using CW signals. Then realtime data transport over the link were carried out using different modulation formats and bandwidths. With 16QAM over a 750 MHz channel a 2.66 Gbit/s data rate was demonstrated with BER<10-11. These tests show that the D-band modules, obtained in a single implementation trial, work well functionally. The interconnect method is applicable to the full D-band and expected to also support frequencies in the sub-millimeter-wave range where traditional methods become challenging to apply.
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| 20. |
- Poole, C., et al.
(författare)
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Design and characterization of a negative resistance Common Emitter InP Double Heterojunction Bipolar Transistor subcircuit for millimeter wave and submillimeter wave applications
- 2014
-
Ingår i: 44th European Microwave Conference, EuMC 2014 - Held as Part of the 17th European Microwave Week, EuMW 2014; Fiera di RomaRome; Italy; 6 October 2014 through 9 October 2014. - 9782874870354 ; , s. 933-936
-
Konferensbidrag (refereegranskat)abstract
- A negative resistance Indium Phosphide MMIC subcircuit element is presented that employs a Double-Heterojunction Bipolar Transistor in Common Emitter configuration with series feedback. The fabricated MMIC exhibits negative resistance up to 231GHz, this being the highest known frequency at which negative resistance has been measured for a transistor in the Common Emitter configuration. The design methodology is based on a simple equation that accurately predicts the value of series feedback reactance required to generate negative resistance in a transistor. The negative resistance subcircuit described has potential application in a reflection amplifier or negative resistance oscillator, when combined with a suitable resonator.
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| 21. |
- Vassilev, Vessen, 1969, et al.
(författare)
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140-220 GHz Imaging Front-end Based on 250 nm InP/InGaAs/InP DHBT Process
- 2013
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819495068 ; 8715
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a pre-amplified detector receiver based on a 250 nm InP/InGaAs/InP double heterojunction bipolar transistor (DHBT) process available from the Teledyne scientific. The front end consists of a double slot antenna followed by a five stage low noise amplifier and a detector, all integrated onto the same circuit. Results of measured responsivity and noise are presented. The receiver is characterized through measuring its response to hot (293) and cold (78) K terminations. Measurements of the voltage noise spectrum at the video output of the receiver are presented and can be used to derive the temperature resolution of the receiver for a specific video bandwidth.
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| 22. |
- Zhu, Changlian, 1964, et al.
(författare)
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Irradiation to the immature brain attenuates neurogenesis and exacerbates subsequent hypoxic-ischemic brain injury in the adult.
- 2009
-
Ingår i: Journal of neurochemistry. - : Wiley. - 1471-4159 .- 0022-3042. ; 111:6, s. 1447-1456
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Cranial radiotherapy is common in pediatric oncology. Our purpose was to investigate if irradiation (IR) to the immature brain would increase the susceptibility to hypoxic- ischemic injury in adulthood. The left hemisphere of postnatal day 10 (P10) mice was irradiated with 8 Gy and subjected to hypoxia-ischemia (HI) on P60. Brain injury, neurogenesis and inflammation were evaluated 30 days after HI. IR alone caused significant hemispheric tissue loss, or lack of growth (2.8 +/- 0.42 mm(3), p<0.001). Tissue loss after HI (18.2 +/- 5.8 mm(3), p<0.05) was synergistically increased if preceded by IR (32.0 +/- 3.5 mm(3), p<0.05). Infarct volume (5.1 +/- 1.6 mm(3)) nearly doubled if HI was preceded by IR (9.8 +/- 1.2 mm(3), p<0.05). Pathological scoring revealed that IR aggravated hippocampal, cortical and striatal, but not thalamic, injury. Hippocampal neurogenesis decreased >50% after IR but was unchanged by HI alone. The number of newly formed microglia was three times higher after IR+HI than after HI alone. In summary, IR to the immature brain produced long-lasting changes, including decreased hippocampal neurogenesis, subsequently rendering the adult brain more susceptible to HI, resulting in larger infarcts, increased hemispheric tissue loss and more inflammation than in non-irradiated brains.
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| 23. |
- Österberg, Klas, 1966, et al.
(författare)
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Personalized tissue-engineered veins - long term safety, functionality and cellular transcriptome analysis in large animals
- 2023
-
Ingår i: Biomaterials Science. - : NLM (Medline). - 2047-4830 .- 2047-4849. ; 11:11, s. 3860-3877
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Tidskriftsartikel (refereegranskat)abstract
- Tissue engineering is a promising methodology to produce advanced therapy medicinal products (ATMPs). We have developed personalized tissue engineered veins (P-TEV) as an alternative to autologous or synthetic vascular grafts utilized in reconstructive vein surgery. Our hypothesis is that individualization through reconditioning of a decellularized allogenic graft with autologous blood will prime the tissue for efficient recellularization, protect the graft from thrombosis, and decrease the risk of rejection. In this study, P-TEVs were transplanted to vena cava in pig, and the analysis of three veins after six months, six veins after 12 months and one vein after 14 months showed that all P-TEVs were fully patent, and the tissue was well recellularized and revascularized. To confirm that the ATMP product had the expected characteristics one year after transplantation, gene expression profiling of cells from P-TEV and native vena cava were analyzed and compared by qPCR and sequencing. The qPCR and bioinformatics analysis confirmed that the cells from the P-TEV were highly similar to the native cells, and we therefore conclude that P-TEV is functional and safe in large animals and have high potential for use as a clinical transplant graft.
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