Sökning: "noise gain"

Visar resultat 16 - 20 av 198 avhandlingar innehållade orden noise gain.

  1. 16. Microwave characterisation of electrodes and field effect transistors based on graphene

    Författare :MICHAEL ANDERSSON; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Graphene; graphene electrodes; microwave amplifiers; noise measurements; microwave FETs; CVD graphene; noise modelling; FBARs.; nanofabrication; subharmonic resistive mixers; small-signal FET modelling;

    Sammanfattning : The isolation of the two-dimensional material graphene, a single hexagonal sheet of carbon atoms, is believed to trigger a revolution in electronics. Theory predicts unprecedented carrier velocities in ideal graphene, from which ultrahigh speed graphene field effect transistors (GFETs) are envisioned. LÄS MER

  3. 17. Phase-Noise Compensation for Space-Division Multiplexed Multicore Fiber Transmission

    Författare :Arni Alfredsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; detection; estimation; space-division multiplexing.; phase noise; multicore fiber; Coherent fiber-optic communications;

    Sammanfattning : The advancements of popular Internet-based services such as social media, virtual reality, and cloud computing constantly drive vendors and operators to increase the throughput of the Internet backbone formed by fiber-optic communication systems. Due to this, space-division multiplexing (SDM) has surfaced as an appealing technology that presents an opportunity to upscale optical networks in a cost-efficient manner. LÄS MER

  4. 18. Study of MgB2 and YBa2Cu3O7-x Microbolometers for THz Sensing Applications

    Författare :Stella Bevilacqua; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; THz Detectors; bolometers; IF bandwidth; YBa2< sub>Cu3< sub>O7-x< sub>; Terahertz frequency; HEB; MgB2< sub>; noise; superconductors;

    Sammanfattning : In this thesis, two novel THz detectors based on magnesium diboride (MgB2)and yttrium barium copper oxide (YBa2Cu3O7-x) are presented. In particular,MgB2 superconductor is used for the investigation of hot-electron bolometer(HEB) mixers, while YBa2Cu3O7-x is explored in microbolometers for room-temperaturecoherent and incoherent detection. LÄS MER

  5. 19. Study of MgB2 HEB mixers at THz frequencies

    Författare :Evgenii Novoselov; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; noise temperature; mixers; bandwidth; THz detectors; superconductors; bolometers; conversion gain; MgB2;

    Sammanfattning : The terahertz (THz) range is very attractive for astronomical observations. Spectroscopy and photometry of remote space objects in the THz range allows for a study of their chemical composition, because this range covers rotational lines from simple molecules and electron transition lines from atoms and ions. LÄS MER

  7. 20. Millimeter and Sub-Millimeter Wave Integrated Active Frequency Down-Converters

    Författare :Yu Yan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 145 GHz; self-oscillating mixer; mixer; conversion gain; millimeter wave; radar; mHEMT; noise figure; monolithic; sub-millimeter wave; InP; THz; resistive mixer; Gilbert mixer; DHBT; SiGe; 340 GHz; 220 GHz; FMCW; transconductance mixer; BiCMOS; transceiver; harmonic; GaAs;

    Sammanfattning : In recent years, the increasing amount of data transmission, the need for automotiveradars, and standoff imaging for security applications are the main factors that accelerateresearch in the millimeter and sub-millimeter wave frequency ranges. The semiconductorindustries have continuously developed their processes, which have opened upopportunities for manufacturing monolithically integrated circuits up to a few hundredGHz, based on transistor technologies. LÄS MER