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Jobs, Magnus
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Publications (10 of 35) Show all publications
Goryashko, V., Jobs, M., Hoang, L., Eriksson, J. & Ruber, R. (2018). 12-Way 100 kW Reentrant Cavity-Based Power Combiner With Doorknob Couplers. IEEE Microwave and Wireless Components Letters, 28(2), 111-113
Open this publication in new window or tab >>12-Way 100 kW Reentrant Cavity-Based Power Combiner With Doorknob Couplers
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2018 (English)In: IEEE Microwave and Wireless Components Letters, ISSN 1531-1309, E-ISSN 1558-1764, Vol. 28, no 2, p. 111-113Article in journal (Refereed) Published
Abstract [en]

We present radio frequency (RF) and thermal characterization of a compact 12-way power combiner designed for operation at 352 MHz at a power level of 100 kW with 5% duty factor. The combiner is based on a reentrant cavity with 12 input doorknob couplers and one output coupler that is integrated with the post of the cavity and forms doorknob type geometry. We introduce convenient design formulas that allow easy identification of a suitable parameter space, which is then refined with numerical simulations. Low-power RF measurements of a prototype show 0.2% insertion loss and a relative rms amplitude imbalance between the ports of 0.1% and phase imbalance of 0.036 degrees rms. The matching is better than -25 dB over a 3-dB bandwidth around the design frequency. We also tested the combiner up to 200 kW and found the RF loss to be comparable to that of the low-power measurement. In a long test run at 100 kW with 5% duty factor, the combiner temperature stabilized at 10 degrees above ambient.

Place, publisher, year, edition, pages
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018
Keywords
High-power handling capability, high-power radio frequency (RF) measurements, power combiner, thermal study
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-349845 (URN)10.1109/LMWC.2017.2780619 (DOI)000425173500007 ()
Available from: 2018-05-03 Created: 2018-05-03 Last updated: 2018-05-03Bibliographically approved
Dancila, D., Hoang Duc, L., Jobs, M., Holmberg, M., Hjort, A., Rydberg, A. & Ruber, R. (2017). A compact 10 kW solid-state RF power amplifier at 352 MHz. Paper presented at 8th International Particle Accelerator Conference 14–19 May 2017, Copenhagen, Denmark. Journal of Physics, Conference Series, 874, Article ID 012093.
Open this publication in new window or tab >>A compact 10 kW solid-state RF power amplifier at 352 MHz
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2017 (English)In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 874, article id 012093Article in journal (Refereed) Published
Abstract [en]

A compact 10 kW RF power amplifier at 352 MHz was developed at FREIA for the European Spallation Source, ESS. The specifications of ESS for the conception of amplifiers are related to its pulsed operation: 3.5 ms pulse length and a duty cycle of 5%. The realized amplifier is composed of eight kilowatt level modules, combined using a planar Gysel 8-way combiner. The combiner has a low insertion loss of only 0.2 dB, measured at 10 kW peak power. Each module is built around a commercially available LDMOS transistor in a single-ended architecture. During the final tests, a total output peak power of 10.5 kW was measured.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-334907 (URN)10.1088/1742-6596/874/1/012093 (DOI)000411396700093 ()
Conference
8th International Particle Accelerator Conference 14–19 May 2017, Copenhagen, Denmark
Projects
ESS
Available from: 2017-11-29 Created: 2017-11-29 Last updated: 2018-03-20Bibliographically approved
Hoang Duc, L., Nguyen Dinh The, A., Bach Gia, D., Jobs, M., Ruber, R. & Dancila, D. (2017). A new high-power low-loss air-dielectric stripline Gysel divider/combiner for particle accelerator applications at 352 MHz. IET Control Theory & Applications
Open this publication in new window or tab >>A new high-power low-loss air-dielectric stripline Gysel divider/combiner for particle accelerator applications at 352 MHz
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2017 (English)In: IET Control Theory & Applications, ISSN 1751-8644, E-ISSN 1751-8652Article in journal (Refereed) Accepted
Abstract [en]

This paper presents a new two-way Gysel combiner based on an air dielectric stripline which allows to handle very highRF power levels with low-loss suitable for power combination in accelerator applications. The insertion loss of the combiner is 0.1dB (2%). A thick stripline implementation allows improving the power capability in both CW and pulsed operation. In addition, amechanical tuner allows compensating for assembly and fabrication discrepancies. A methodology of design the Gysel combineris presented as well as high power measurements up to 22 kW in pulsed mode. Simulations and measurements are in very goodagreement.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-334913 (URN)
Projects
ESS
Available from: 2017-11-29 Created: 2017-11-29 Last updated: 2017-12-01Bibliographically approved
Santiago Kern, R., Bhattacharyya, A., Gajewski, K., Goryashko, V., Hermansson, L., Jobs, M., . . . Ruber, R. (2017). Cryogenic Synopsis from the Testing of the Fully Equipped ESS’ Double Spoke Cavity Romea. Uppsala
Open this publication in new window or tab >>Cryogenic Synopsis from the Testing of the Fully Equipped ESS’ Double Spoke Cavity Romea
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2017 (English)Report (Other academic)
Place, publisher, year, edition, pages
Uppsala: , 2017. p. 29
Series
FREIA Report ; 2017/12
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-333037 (URN)
Available from: 2017-11-06 Created: 2017-11-06 Last updated: 2017-11-09Bibliographically approved
Jobs, M., Wedberg, R. & Gajewski, K. (2017). DB Science 400 kW RF Station Site Acceptance Test.
Open this publication in new window or tab >>DB Science 400 kW RF Station Site Acceptance Test
2017 (English)Report (Other (popular science, discussion, etc.))
Abstract [en]

The manufactured and delivered DB-Science 400 kW RF station was tested on site at FREIA during 2016. The station can successfully deliver continuous pulse-trains with a power-level up to 400 kW, however during most of the on-site measurements and testing the total combiner output power was limited to 360 kW due to unusually high G2 currents measured in one of the spare TH595 tetrode tubes used in the station. Each of the stations 200 kW tetrode based amplifier sections were mounted with TH595 tetrode tubes from Thales and tuned for optimal performance. The gain of the tetrode amplifiers were roughly 15 dB with some variation between the two amplifier sections and the overall gain was approximately 74 dB maximum. Amplitude and phase pulse variations were within the specified levels.

Series
FREIA Report ; 2017/01
Keywords
FREIA, ESS, RF, High Power, Tetrode, Amplifier, Test, Evaluation, Prototype
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-313316 (URN)
Available from: 2017-01-19 Created: 2017-01-19 Last updated: 2017-01-23Bibliographically approved
Li, H., Santiago-Kern, R., Jobs, M., Bhattacharyya, A., Goryashko, V., Hermansson, L., . . . Ruber, R. (2017). First High Power Test of the ESS Double Spoke Cavity. Uppsala
Open this publication in new window or tab >>First High Power Test of the ESS Double Spoke Cavity
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2017 (English)Report (Other academic)
Abstract [en]

The first double spoke cavity for ESS project was tested with high power in the HNOSS cryostat at FREIA Laboratory. This cavity is designed for 325.21MHz, a pulse mode with 14 Hz repetition rate, up to peak power of 360 kW. The qualification of the cavity package in a high power test, involved a spoke superconducting cavity, a fundamental power coupler, LLRF system and a RF station, represented an important verification before the module assembly. This report presents the test configuration, RF conditioning history and first high power performance of this cavity package.

Place, publisher, year, edition, pages
Uppsala: , 2017. p. 60
Series
FREIA Report ; 2017/10
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-335434 (URN)
Available from: 2017-12-05 Created: 2017-12-05 Last updated: 2017-12-06Bibliographically approved
Jobs, M., Wedberg, R., Roger, R. & Dancila, D. (2016). High Power Microwave Technology in ESS & FREIA. In: : . Paper presented at GigaHertz Symposium.
Open this publication in new window or tab >>High Power Microwave Technology in ESS & FREIA
2016 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-288572 (URN)
External cooperation:
Conference
GigaHertz Symposium
Available from: 2016-04-28 Created: 2016-04-28 Last updated: 2016-08-30
Dancila, D., Hoang Duc, L., Jobs, M., Goryashko, V., Rydberg, A., Olsson, J. & Ruber, R. (2016). Preliminary measurements of eight solid-statemodules of the 10 kW pulsed power amplifier at 352 MHz under development at FREIA. In: : . Paper presented at Ninth CW and High Average Power RF Workshop,21-24 June, Grenoble, France.
Open this publication in new window or tab >>Preliminary measurements of eight solid-statemodules of the 10 kW pulsed power amplifier at 352 MHz under development at FREIA
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2016 (English)Conference paper, Oral presentation with published abstract (Refereed)
Keywords
power amplifier, microwaves, particle accelerator
National Category
Accelerator Physics and Instrumentation Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-295215 (URN)
Conference
Ninth CW and High Average Power RF Workshop,21-24 June, Grenoble, France
Available from: 2016-06-03 Created: 2016-06-03 Last updated: 2016-06-27Bibliographically approved
Wu, Z., Jobs, M., Rydberg, A. & Hjort, K. (2015). Hemispherical coil electrically small antenna made by stretchable conductors printing and plastic thermoforming. Journal of Micromechanics and Microengineering, 25(2), Article ID 027004.
Open this publication in new window or tab >>Hemispherical coil electrically small antenna made by stretchable conductors printing and plastic thermoforming
2015 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, no 2, article id 027004Article in journal (Refereed) Published
Abstract [en]

A production scalable technique is presented to make hemispherical coil antennas by using a stretchable printed silver paste conductor and plastic thermoforming. To ease the fabrication process an unbalanced feed-structure was designed for solderless mounting on conductive materials. The manufactured antenna had a resonance frequency of 2.467 GHz with a reflection coefficient of -33.8 dB. The measured and simulated radiation patterns corresponded to that of monopole structure and the measured efficiency was 40%.

National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Microsystems Technology; Engineering Science with specialization in Electronics
Identifiers
urn:nbn:se:uu:diva-238904 (URN)10.1088/0960-1317/25/2/027004 (DOI)000349106800024 ()
Available from: 2014-12-17 Created: 2014-12-17 Last updated: 2017-12-05Bibliographically approved
Jobs, M., Wedberg, R. & Gajewski, K. (2015). Itelco-Electrosys 400 kW RF Station Site Acceptance Test. Uppsala: Uppsala University, Department of Physics and Astronomy
Open this publication in new window or tab >>Itelco-Electrosys 400 kW RF Station Site Acceptance Test
2015 (English)Report (Other (popular science, discussion, etc.))
Abstract [en]

The manufactured and delivered Itelco-Electrosys 400 kW RF station was tested on site at FREIA, in Uppsala August 31 through September 4 2015. The station could successfully deliver continuous pulsetrains with a power-level up to 400 kW. Each of the stations 200 kW tetrode based amplifier sections were mounted with TH-595 tetrode tubes from Thales and tuned for optimal performance. The gain of the tetrode amplifiers were roughly 15 dB with some variation between the two amplifier sections andthe overall gain was approximately 85 dB maximum.Some droop and phase distortion on the combined output pulse was measured caused primarily by a limited response time of the screen-grid power supply.

Place, publisher, year, edition, pages
Uppsala: Uppsala University, Department of Physics and Astronomy, 2015. p. 35
Series
FREIA Report ; 2015/07
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-263018 (URN)
Available from: 2015-09-24 Created: 2015-09-24 Last updated: 2015-10-05Bibliographically approved
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