| 1. |
- Güsten, R., et al.
(författare)
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APEX - The Atacama Pathfinder Experiment
- 2006
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 6267 I
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Konferensbidrag (refereegranskat)abstract
- APEX, the Atacama Pathfinder Experiment, has been successfully commissioned and is in operation now. This novel submillimeter telescope is located at 5107 m altitude on Llano de Chajnantor in the Chilean High Andes, on what is considered one of the world's outstanding sites for submillimeter astronomy. The primary reflector with 12 m diameter has been carefully adjusted by means of holography. Its surface smoothness of 17-18 μm makes APEX suitable for observations up to 200 μm, through all atmospheric submm windows accessible from the ground.
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| 2. |
- Belitsky, Victor, 1955, et al.
(författare)
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Superconducting microstrip line models at millimeter and sub-millimeter waves and their comparison
- 2003
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Ingår i: Proceedings of the 14th International Symposium on Space and Terahertz technology. ; , s. 456-475
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Konferensbidrag (refereegranskat)abstract
- Performance of superconductor — insulator - superconductor (SIS) tunnel junction mixers andtheir instantaneous input RF bandwidth are mostly depending on the integrated tunin g circuit used to resonate out SIS junction capacitance; Nb-based SIS mixers operate in the frequency range of about 80 - 1000 GHz and typically use microstrip-based integrated tuning circuitries.One of the major challenges in designing the tuning circuitry for SIS mixers is accuracy of models for superconducting microstrip line (SML). Modeling gives the only tool to solve the problem of designing SML-based circuits because for such high frequencies no direct measurements of a superconducting transmission line can be made with required high accuracy.However, creating an accurate model for such a superconducting transmission line is a challengeby itself. In the SML, produced usually by thin-film technology, the magnetic field penetrationdepth is comparable with the thicknesses of the dielectric and superconductors comprising theline. As a result the electromagnetic wave is propagated not only in the dielectric media but alsoinside the superconducting strip and ground electrodes constituting the SML. This createsdramatic changes in the transmission line behavior that should be carefully accounted byincluding the superconducting material properties into the modeling. Nb superconductor, as themost commonly exploited material, was used in this study for modeling of the superconductingmicrostrip though the same approach would work for any different BCS superconductingmaterial. The purpose of this paper is to introduce a new model for SML and compare it withpreviously suggested models and results of SML numerical simulation.
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| 3. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
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Compact Low-Loss Chip-to-Waveguide and Chip-to-Chip Packaging Concept Using EBG Structures
- 2021
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 31:1, s. 9-12
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Tidskriftsartikel (refereegranskat)abstract
- This letter presents a novel approach for packaging millimeter-wave (mmW) and terahertz (THz) circuits. The proposed technique relies on using an on-chip coupling structure that couples the signal to a quarter-wavelength cavity, which in turn couples to either a waveguide (WG) or another chip. The solution also uses a periodic electromagnetic bandgap (EBG) structure that controls the electromagnetic wave and prevents field leakage in undesired directions. The proposed solution is fabricated and demonstrated at the D-band (110-170 GHz), and the measurement results show that it achieves a minimum insertion loss of 0.8 and a 3-dB bandwidth extending from 124 to 161 GHz. The proposed approach does not require any galvanic contacts and can be used for packaging integrated circuits in WG modules as well as for chip-to-chip communication.
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| 4. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
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D-band waveguide-to-microstrip transition implemented in eWLB packaging technology
- 2020
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 56:4, s. 187-
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Tidskriftsartikel (refereegranskat)abstract
- This Letter presents a non-galvanic D-band (110-170 GHz) interconnect realised in embedded wafer level ball grid array (eWLB) packaging technology. The interconnect consists of a patch-radiator-based waveguide transition implemented using one of the technology's redistribution layers. The patch radiates to a WR-6.5 standard waveguide perpendicular to its plane. An electromagnetic band-gap structure realised by metal patches is used to suppress undesired modes and improve the performance of the transition. The proposed solution is experimentally verified, and measurement results show that the transition exhibits an average insertion loss of 2 dB across the frequency range 122-146 GHz which, to the best of the authors' knowledge, is the lowest reported loss for a D-band packaging solution in eWLB technology and hence addresses one of the main integration challenges facing millimetre-wave systems.
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| 5. |
- Ren, Qiannan, 1994, et al.
(författare)
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Millimeter-Wave Vertical Transitions between Ridge Gap Waveguides and Microstrip Lines for Integration of MMIC with Slot Array
- 2021
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Ingår i: 15th European Conference on Antennas and Propagation, EuCAP 2021.
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Konferensbidrag (refereegranskat)abstract
- This paper presents two low-loss vertical transitions between ridge gap waveguides and microstrip lines. The transitions can be utilized as packaging techniques for system level integration of MMICs with waveguide components such as slot array antennas. Both vertical transitions feature microstrip lines being the bottom layer but facing opposite directions. The first vertical transition consists of a microstrip line facing upwards with a patch in the end. Simulation results show that the reflection coefficient is better than -15 dB from 74 to 82 GHz. The second transition of microstrip line facing downwards features E-plane probe with back-short cavity surrounded by periodic pins. Simulation results show that the reflection coefficient is better than -15 dB from 71 to 86 GHz. Comparing with other same layer transitions, the vertical solutions provide more flexibility for the routing of antenna feeding line and have the ability of implementing a more compact design.
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| 6. |
- 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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| 7. |
- Albadalejo Lijarcio, Juan Luis, 1994, et al.
(författare)
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Substrate-Less Vertical Chip-to-Waveguide Transition for W-Band Array Antenna Integration
- 2023
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Ingår i: 2023 17TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION, EUCAP. - 2164-3342. - 9788831299077
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Konferensbidrag (refereegranskat)abstract
- This paper presents a vertical transition from a high permittivity GaAs MMIC to rectangular waveguide using bondwires as a coupling structure. The transition is advantageous for the direct integration of any off-the-shelf chip into a waveguide antenna since no modification of the GSG-pad or additional substrate is needed. An EBG structure consisting of pins is used for the packaging of the chip in order to avoid field propagation in undesired directions. The simulations results show that the reflection coefficient is lower than -10 dB and the average insertion loss is better than 0.5 dB from around 87 to 101 GHz (14% relative bandwidth).
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| 8. |
- Auriacombe, Olivier, 1989, et al.
(författare)
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Oil, water, and ice detection on road surfaces with a millimeter-wave radiometer
- 2020
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 11533
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Konferensbidrag (refereegranskat)abstract
- Passive radiometers are well-known instruments used in the characterization of soil, sea surfaces and remote sensing of the earth atmosphere with satellites or airplanes. The instrument described in this article is a dual-polarised superheterodyne radiometer operating around 93 GHz. It is placed on a structure to measure road surface conditions (ice, water or oil) in a laboratory-controlled environment. This radiometer measures the reflected and emitted radiations from the road surface (asphalt and concrete) and the background temperature, in two orthogonal polarizations (H and V). The difference in the dielectric properties of the ice, oil and water from dry road surface allows to distinguish them efficiently. This kind of technique can be used for road surface recognition in all weather conditions and does not require presence of daylight or other sources of illumination. In this paper, calibration procedures and radiometric characterisations of the radiometer are studied in order to select the best and simpler method to operate the radiometer. It was found that calibrating the radiometer with only one blackbody target or using a table of gain and system noise temperature is sufficiently accurate over a long time to be able to distinguish dry from ice or water covered surfaces. The laboratory results are showing a high difference in the brightness temperature between road surface covered with ice, water or oil and the dry road surface. No ambiguities between those conditions exist but potential limitations could rise, for example if the road surface roughness changes during a measurement. Those promising results validate the potential of using radiometer for road safety and the automotive industry. The presented laboratory measurements are the first step towards the implementation of the instrument into a moving vehicle for alerting drivers ahead of unforeseen dangers. Downloading of the abstract is permitted for personal use only.
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| 9. |
- Carpenter, Sona, 1983, et al.
(författare)
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A +14.2 dBm, 90–140 GHz Wideband Frequency Tripler in 250-nm InP DHBT Technology
- 2018
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 28:3, s. 239-241
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Tidskriftsartikel (refereegranskat)abstract
- A single-chip active frequency tripler circuit with output at F-band (90-140 GHz) is presented. A common-emitter transistor stage with input and output matching circuits is used to produce the third harmonic, followed by a five-pole bandpass filter and a wideband four-stage power amplifier to amplify and increase the output power. The circuit is implemented in a 250-nm InP double-heterostructure bipolar transistor technology with ft/fmax 350/650 GHz, respectively. The chip achieves a peak output power of 14.2 dBm from 99 to 126 GHz at 2-dBm input power and conversion gain of 13 dB at -2-dBm input power. The measured 3-dB output bandwidth is 51 GHz from 90 to 141 GHz which corresponds to 44.2% relative bandwidth. It demonstrates up to 23-dBc rejection ratio of the first and the second harmonics. The dc power consumption is 156 mW at 2-dBm input power. The chip size is 0.9 × 0.96 mm2 including pads and achieves a power efficiency of 16.7%.
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| 10. |
- Dochev, Dimitar Milkov, 1981, et al.
(författare)
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Superconducting IF biasing circuit for low-noise cryogenic applications
- 2010
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 234:4
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Konferensbidrag (refereegranskat)abstract
- A planar superconducting circuit designed for use in low-noise cryogenic applications is presented. The circuit is a bias-T combined with a 4–8 GHz impedance matching circuitry, which employs entirely planar design with a novel layout. The proposed and tested circuitry is intended to be used with a SIS mixer and incorporates a double section transformer based on microstrip line technology with a total impedance transformation of 5:1 within the frequency band. One of the transformer sections employs a three-line coupled line, which also serves as a DC block capacitor. The microstrip lines were manufactured using superconducting Nb metallization, which provides a conduction loss-free solution at the operation temperature of 4 K. S-parameter measurements at 4 K temperature were performed and found to be in a good agreement with the simulations. The device measured return loss is better than −10 dB within the frequency band. Furthermore, the circuit was tested as a part of 385 – 500 GHz double sideband heterodyne SIS receiver demonstrating a flat noise temperature response of 80 – 90 K over the entire IF band of 4 – 8 GHz.
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