| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Shiu, Jin-Yu, 1978, et al.
(författare)
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Oxygen Ion Implantation Isolation Planar Process for AlGaN/GaN HEMTs
- 2007
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Ingår i: IEEE Electron Device Letters. ; 28:6, s. 476-478
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Tidskriftsartikel (refereegranskat)abstract
- A multienergy oxygen ion implantation process wasdemonstrated to be compatible with the processing of highpower microwave AlGaN/GaN high electron mobility transistors (HEMTs). HEMTs that are isolated by this process exhibited gate-lag- and drain-lag-free operation. A maximum output power density of 5.3 W/mm at Vgs = −4 V and Vds = 50 V and a maximum power added efficiency of 51.5% at Vgs = −4 V and Vds = 30 V at 3 GHz were demonstrated on HEMTs withoutfield plates on sapphire substrate. This isolation process results in planar HEMTs, circumventing potential problems with enhancedgate leakage due to the gate contacting the 2-D electron gas at themesa sidewall.
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| 3. |
- Desmaris, Vincent, 1977, et al.
(författare)
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Influence of oxynitride (SiOxNy) passivation on the microwave performance of AlGaN/GaN HEMTs
- 2008
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Ingår i: Solid-State Electronics. ; 52, s. 632-636
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Tidskriftsartikel (refereegranskat)abstract
- The effects of the composition of oxynitride passivations (SiOxNy) deposited by plasma enhanced chemical-vapor deposition (PECVD) at room temperature on the microwave performance of AlGaN/GaN high electron mobility transistors (HEMTs) were investigated. Five different SiOxNy passivating layers were deposited covering the whole range of dielectrics combinations from SiOx to SiNy. Their impacts on the HEMT performance were studied by means of DC, S-parameters, pulsed IV and load-pull measurements. The oxynitride dielectric with a refraction index of 1.58 was shown to be an effective SiOxNy passivation for limiting the gate-lag effects in the HEMTs and at the same time increasing the breakdown voltage of the device. It is thus a promising passivation layer for microwave power high voltage and high power applications.
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| 4. |
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| 5. |
- Fhager, Andreas, 1976, et al.
(författare)
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Microwave Technology in Medical Diagnostics and Treatment
- 2015
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Ingår i: 2015 Ieee Mtt-S International Microwave Workshop Series on Rf and Wireless Technologies for Biomedical and Healthcare Applications. - New York : Ieee. - 9781479985432 ; , s. 133-134
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- There is a great need for novel diagnostics and treatment tools in today's healthcare. In this paper we describe our development and progress in novel microwave based diagnostics and treatment applications. The target applications are stroke diagnostics, breast cancer detection and microwave hyperthermia.
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| 6. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
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Nongalvanic Generic Packaging Solution Demonstrated in a Fully Integrated D-Band Receiver
- 2020
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Ingår i: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 10:3, s. 321-330
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a packaging technique for monolithic microwave integrated circuits (MMIC) demonstrated in a fully integrated receiver (Rx) module at the D -band (110–170 GHz). The solution consists of an MMIC-to-waveguide transition realized using an on-chip probe mounted in the E -plane of a split-block waveguide module. An artificial magnetic conductor structure is implemented to suppress cavity modes and achieve better coupling from the waveguide to the probe. The transition's performance is experimentally verified using a back-to-back test chip, and measurement results show that the proposed packaging solution achieves a low insertion loss of only 0.7 dB and covers a very wide frequency range extending from 105 to 175 GHz. The proposed transition is also integrated with an in-phase/quadrature-phase (I/Q) Rx on the same chip. The Rx is realized in a 250-nm indium phosphide double heterojunction bipolar transistor technology and consists of a low-noise amplifier, an I/Q mixer, and a frequency tripler. Measurement results show that the Rx module achieves an average conversion gain of 23 dB across the frequency range of 110–145 GHz and has an average noise figure of 10.6 dB. The Rx MMIC has a dc power consumption of 440 mW and occupies an area of 1.6 × 1.6 mm 2 . This article addresses one of the main challenges in systems operating above 100 GHz and presents a fully integrated packaging solution that suits large integrated circuits and does not require any galvanic contacts nor impose any limitations on MMIC dimensions.
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| 7. |
- Karandikar, Yogesh, 1982, et al.
(författare)
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A compact 340 GHz 2x4 patch array with integrated subharmonic gilber core mixer as a building block for multi-pixel imaging frontends
- 2014
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Ingår i: Technical Digest - IEEE Compound Semiconductor Integrated Circuit Symposium, CSIC. - 1550-8781. - 9781479936229
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Konferensbidrag (refereegranskat)abstract
- For linear multi-pixel imaging systems, a linear stack of pixels comprising of an antenna and a heterodyne receiver are needed. Such pixels can be realized using MMIC processes. The main constraint for such multi-pixel system is a compact array of pixels giving high coupling to quasi-optics used for focusing. This paper addresses this trade-off and presents a novel solution based on beam synthesis of two consecutive subarrays. One such sub-array along with heterodyne receiver is described as half-pixel in this paper and it is realized using 2x4 patch array and Gilbert core sub-harmonic mixer using a 250nm DHBT process. The patch array has ohmic loss better than 8 dB and mixer conversion loss is 6-8 dB over 320-350 GHz RF band. The chip size is 1mm x 2mm and therefore for 7 simultaneous beams a MMIC of 8 half-pixels is foreseen.
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| 8. |
- Karandikar, Yogesh, 1982, et al.
(författare)
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Compact integration of sub-harmonic resistive mixer with differential double slot antenna in G-band using 50nm InP-HEMT MMIC process
- 2012
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Ingår i: 2012 IEEE Compound Semiconductor Integrated Circuit Symposium, CSICS 2012, La Jolla, CA, 14 - 17 October 2012. - 1550-8781. - 9781467309295
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Konferensbidrag (refereegranskat)abstract
- Sub-Harmonic resistive HEMT based mixers in Gband have been designed and integrated with Double Slot Antenna in Differential Configuration for the first time. This novel topology shows compact integration of active devices between antenna ports while achieving 25 GHz bandwidth around 200 GHz. The dual-gate 50nm x 15um InP HEMT used in the design achieves the conversion loss of 15 dB with +3 dBm LO power drive. Furthermore, a similar topology when used as a Harmonic mixer using a single gate device offers 16.5 dB conversion loss for +4 dBm LO power. For compact integration, via hole matching on slot antenna is also presented.
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| 9. |
- Persson, Mikael, 1959, et al.
(författare)
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Microwave based diagnostics and treatment in practice
- 2013
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Ingår i: 2013 IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications, IMWS-BIO 2013 - Proceedings.
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Konferensbidrag (refereegranskat)abstract
- Globally, around 15 million people each year suffer a stroke. Only a small fraction of stroke patients who could benefit from thrombolytic treatment reach diagnosis and treatment in time. To increase this low figure we have developed microwave technology aiming to differentiate hemorrhagic from ischemic stroke patients. The standard method for breast cancer diagnosis today is X-ray mammography. Despite its recognized ability to detect tumors it suffers from some limitations. Neither the false positive nor the false negative detection rates are negligible. An interesting alternative being researched extensively today is microwave tomography. In our current strive to develop a clinical prototype we have found that the most suitable design consists of an antenna array placed in a full 3D pattern. During the last decade clinical studies have demonstrated the ability of microwave hyperthermia to dramatically enhance cancer patient survival. The fundamental challenge is to adequately heat deep-seated tumors while preventing surrounding healthy tissue from undesired heating and damage. We are specifically addressing the challenge to deliver power levels with spatial control, patient treatment planning, and noninvasive temperature measurements. © 2013 IEEE.
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| 10. |
- Shiu, Jin-Yu, 1978, et al.
(författare)
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Comparison of the DC and microwave performance of AlGaN/GaN HEMTs with sputter PVD or plasma enhanced CVD grown silicon nitride (SiNx) passivation layer
- 2006
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Ingår i: WOCSDICE 2006 Proceedings, Fiskebäckskil 2006.
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Konferensbidrag (refereegranskat)abstract
- Sputter and plasma enhanced chemical vapor deposition (PECVD) processed SiNx passivation layer on AlGaN/GaN high electron mobility transistors (HEMTs) was compared in this investigation. The both samples were process on the same wafer and the same process besides the passivation process in the same batch. From the data of DC, mimicked class B quiescent bias point pulse measurement, transient pulse measurement are showing that the sputter passivation HEMTs have better performance because there are fewer surface traps. The power sweep data from load pull measurement were in accordance with the pulsed measurement data. Without cooling, continuous wave power densities of 4W/mm and 3.1W/mm was measured at 3GHz on the sputter and PECVD passivation HEMTs, respectively.
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