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This study addresses the modelling of a dual band (28 and 38 GHz), circularly polarised slotted-patch-antenna for highly demanded millimetre wave multi-input multi-output (MIMO)-systems in fifth generation (5G) networks. A computer-aided-design model is derived by means of an artificial neural network (ANN) which allows obtaining the physical dimensions of a single-fed antenna, satisfying both nea
The finite-difference time-domain (FDTD) method is used for the large-signal modeling of a multifinger pHEMT, which is considered as five nonlinear coupled distributed transmission lines. The developed model, which is based on the exact physical layout of multifinger pHEMT, not only accurately describes the propagation effects along the electrodes at higher frequencies but it also includes major n
In this paper, one simple dual-band (28 and 38 GHz) circularly polarized slotted patch antenna, suitable for future millimeter wave mobile communication, is presented. The proposed monolayer circularly polarized patch antenna is considered without any 90° phase shifter and is excited by a single-feed microstrip line, which is very desirable for high gain antenna array implementation in millimeter
A multiple-input-multiple-output (MIMO) dual-band antenna system consisting of two elements, each of which built up of circularly polarized slotted patch antenna for mm-wave band 5G wireless handheld and portable terminals is described. Space diversity is used to achieve a good independent channel fading in MIMO systems. In theoretical analysis of MIMO systems often assume that each antenna is iso
The overall designing of one 90nm CMOS reflective-type phase shifter for the first three channels in 60 GHz band is described. The performance investigation is based on full wave electromagnetic analysis and optimization. The simulation predicts a phase tuning range of 360° as a function of control voltage with an average insertion loss of 5.5 dB over all phase states. The linearity of the phase s
The overall circuit designing of one path phased array transmitter consisting of 90 nm CMOS integrated power amplifier and passive phase shifter for the first three channels in 60 GHz band, is described. The performance investigation is based on a hybrid analysis and optimization. It consists of both electromagnetic (Method of Moments (MOM)) analysis for improving the accuracy of the models in thi
A new fully-integrated concurrent dual band CMOS power amplifier (PA) which covers the first and third channels of IEEE 802.15.3c standard is presented. In order to achieve concurrent operation of the 60 GHz PA in two desired narrow frequency bands, the multi-frequency passive coupling matching networks design is proposed. The full wave electromagnetic analysis (by the conventional Method of Momen
To support countries in reforming their research and innovation systems, the Directorate-General for Research & Innovation (DG RTD) of the European Commission set up a Policy Support Facility (PSF) under the European Framework Programme for Research & Innovation ‘Horizon 2020’. It aims to support Member States and associated countries in improving their national science, technology and inn
This book analyzes the current trends in the production, dissemination, and use of knowledge which contribute to social inequalities, especially in the Global South. The aim of the text is to explore the possibilities of active involvement by universities in the democratization of knowledge - a process by which people will be able to more easily acquire and utilize knowledge, as well as the result
Hard X-ray diffraction (XRD) using a nanofocused beam is used to measure both lattice contraction and bending in a single nanowire device under electric bias. The shape of the nanowire is reconstructed in 3D with sub-nanometer precision. As the bias voltage is gradually increased, nonreversible structural changes in the contact regions are observed, correlated with degradation of the electrical co
Simultaneous scanning Bragg contrast and small-angle ptychographic imaging of a single solar cell nanowire are demonstrated, using a nanofocused hard X-ray beam and two detectors. The 2.5 μm-long nanowire consists of a single-crystal InP core of 190 nm diameter, coated with amorphous SiO2 and polycrystalline indium tin oxide. The nanowire was selected and aligned in real space using the small-angl
Hard x-ray focusing and imaging on the few nano metre scale has gained a lot of attraction in the last couple of years. Thanks to new developments in fabrication and inspection of high-N.A. optics, focusing of hard x-rays has caught up with the focusing performance for soft x-rays. Here we review the latest imaging experiments of the Göttinger Multilayer zone plate collaboration, summarising our r
This article describes holographic imaging experiments using a hard X-ray multilayer zone plate (MZP) with an outermost zone width of 10nm at a photon energy of 18keV. An order-sorting aperture (OSA) is omitted and emulated during data analysis by a 'software OSA'. Scanning transmission X-ray microscopy usually carried out in the focal plane is generalized to the holographic regime. The MZP focus
We present a fabrication scheme of contacting arrays of vertically standing nanowires (NW) for LEDs (Duan et al. Nature 409:66–69, 2001), photodetectors (Wang et al. Science (NY) 293:1455–1457, 2001) or solar cell applications (Wallentin et al. Science (NY) 339:1057–1060, 2013). Samples were prepared by depositing Au films using nano-imprint lithography (Ma rtensson et al. Nano Lett 4:699–702, 200
Suitable detection systems that are capable of recording high photon count rates with single-photon detection are instrumental for coherent X-ray imaging. The new single-photon-counting pixel detector 'Lambda' has been tested in a ptychographic imaging experiment on solar-cell nanowires using Kirkpatrick-Baez-focused 13.8 keV X-rays. Taking advantage of the high count rate of the Lambda and dynami
Waveguiding of excitation beam and propagation of THz beam in a complex gradient environment were studied in an array of InP nanowires. Measurements by time-resolved THz spectroscopy accompanied by Monte-Carlo calculations of the response of localized charges enabled determination of transversal electron mobility.
