A5038234964- Superconducting and THz Device Technology
- Radio Astronomy Observations and Technology
- Microwave Engineering and Waveguides
- Photonic and Optical Devices
- Gyrotron and Vacuum Electronics Research
- Advanced Antenna and Metasurface Technologies
- Electromagnetic Scattering and Analysis
- Antenna Design and Optimization
- Optical Coatings and Gratings
- Advanced Thermodynamic Systems and Engines
- Cosmology and Gravitation Theories
- Acoustic Wave Resonator Technologies
- Advanced Fiber Laser Technologies
- Particle accelerators and beam dynamics
- Galaxies: Formation, Evolution, Phenomena
- Scientific Research and Discoveries
- Semiconductor Lasers and Optical Devices
- Microwave and Dielectric Measurement Techniques
- Photonic Crystals and Applications
- Electromagnetic Compatibility and Measurements
- Numerical methods for differential equations
- Electromagnetic Simulation and Numerical Methods
- Advanced Photonic Communication Systems
- Advanced Frequency and Time Standards
- Advanced Research in Systems and Signal Processing
Gazi University
2014-2019
National University of Ireland, Maynooth
2005-2018
National Academy of Sciences of Ukraine
1997-2014
O.Ya. Usikov Institute for Radiophysics and Electronics
1998-2014
National University of Ireland
2001-2006
Bilkent University
1997-2002
National Technical University "Kharkiv Polytechnic Institute"
1993-2002
Pskov State University
1989
Institute of Radio-Engineering and Electronics
1989
<i>Context. <i/>The High Frequency Instrument (HFI) is one of the two focal instruments <i>Planck<i/> mission. It will observe whole sky in six bands 100 GHz–1 THz range.<i>Aims. HFI instrument designed to measure cosmic microwave background (CMB) with a sensitivity limited only by fundamental sources: photon noise CMB itself and residuals left after removal foregrounds. The high frequency provide full maps submillimetre sky, featuring mainly extended point source Systematic effects must be...
<i>Planck<i/> is a scientific satellite that represents the next milestone in space-based research related to cosmic microwave background, and many other astrophysical fields. was launched on 14 May of 2009 now operational. The uncertainty optical response its detectors key factor allowing achieve objectives. More than decade analysis measurements have gone into achieving required performances. In this paper, we describe main aspects optics are relevant science, estimated in-flight...
<i>Planck<i/> is a European Space Agency (ESA) satellite, launched in May 2009, which will map the cosmic microwave background anisotropies intensity and polarisation with unprecedented detail sensitivity. It also provide full-sky maps of astrophysical foregrounds. An accurate knowledge telescope beam patterns an essential element for correct analysis acquired data. We present detailed description optical design High Frequency Instrument (HFI) together some performances measured during...
The <i>Planck<i/> High Frequency Instrument, HFI, has been designed to allow a clear unobscured view of the CMB sky through an off-axis Gregorian telescope. prime science target is measure polarized anisotropy with sensitivity 1 part in 10<sup>6<sup/> maximum spatial resolution 5 arcmin (<i>C<i/><sub><i>l<i/><sub/> ~ 3000) four spectral bands two further high-frequency channels measuring total power for foreground removal. These requirements place critical constraints on both telescope...
Accurate numerical optimization based on rigorous solution of the integral equation using method analytical regularization is performed for a cylindrical reflector antenna in dielectric radome. It shown that multiple scattering this system more significant optimum radome design than any nonplane-wave effects or curvature We claim that, although common half-wavelength good approximation to avoid negative (such as loss directivity), one can, by carefully playing with thickness, its radius,...
The ESA Planck satellite has begun studying the anisotropies of cosmic microwave background radiation over whole sky with unprecedented sensitivity and high angular resolution. High Frequency Instrument, HFI, on is observing simultaneously in six bands range 100 GHz to 857 GHz. inclusion non-CMB allows for robust removal foreground sources from data. This paper concerned design, modeling predicted performances two highest frequency channels centered 545 GHz, which use specialized multi-mode...
Measurement of cosmic microwave background polarization is today a major goal observational cosmology. The level the signal to measure, however, makes it very sensitive various systematic effects. In case Planck, which measures by combining data from detectors, beam asymmetry can induce conversion temperature signals or mode mixing. this paper, we investigate effect using realistic simulated beams and propose first-order method correct power spectra for induced effect.
Measurements of mm-wave excitation spectra highorder whispering gallery modes in free-space cylindrical disk resonators as functions resonator thickness have been made. Resonators the form tight stacks thin dielectric disks excited via waveguides used experiment. Experimental conditions for thin-disk found. A simple approach modeling and recovery parameters has proposed.
We present experimental investigation of light-controlled photonics-enhanced quasi-optical mm-wave beam switch operating at a resonant frequency in the band 75 to 110 GHz. The is implemented as Bragg structure with layer high-resistivity silicon that creates narrow transmission peak within propagation gap. amplitude sensitive intensity light pulses illuminating structure. When using wafer 30 KOhm · cm resistivity and created by 400W LED-array source, we achieved modulation exceeding 15 dB.
Accurate numerical analysis of a two-dimensional (2-D) variable-resistivity reflector has been carried out by the method regularization based on analytical inversion corresponding static problem. The complex source-point model used to account for directivity feeder and both H- E-polarization cases are considered. Far-field radiation patterns, directivity, total radiative power have computed reflectors uniform nonuniform resistivities. concept edge loading control improvement antenna...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation V. B. Yurchenko; Answer to Question #79. Does plane wave not carry a spin?. Am. J. Phys. 1 June 2002; 70 (6): 568–569. https://doi.org/10.1119/1.1463741 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Dropdown Menu input auto suggest...
Design, fabrication and focal field measurements of W-band Fresnel lenses to produce well-shaped Gaussian beams in the domain are presented. Two lenses, one Teflon another Polyamide, have been compared their performance with a double-sided lens different design, full height steps. Experiments show that good focusing ability all is achieved. They target beam according design. Yet, split-step design thinner, lower insertion losses, greater depth as more conventional lenses.
We present our developments in computer simulations and optimization of compound parabolic concentrators (CPCs) for solar heat collectors. Issues both the optical thermal CPC collectors enclosed design are discussed. Ray tracing results a with V-shaped absorber presented. A range optimal values apex angle is proposed collector typical design.
Optical design in the terahertz (THz) waveband can be challenging, especially for high-precision applications. In this paper we summarise our experience with quasi-optical and subsequent performance of astronomical telescopes designed to measure faint temperature polarisation properties Cosmic Microwave Background Radiation, particular QUaD<sup>1</sup>, PLANCK Surveyor<sup>2</sup> MBI<sup>3</sup>. These contain a range components including corrugated feed horns, on- off-axis conic mirrors...
In our work, we perform numerical simulations of multi-layer subwavelength grid THz polarizers and evaluate their efficiency as a function various design parameters.
A high-Q re∞ection notch method for measuring large dielectric losses in absorbing materials when using a stack resonator, which is one-dimensional analogue of capillary-in-a-waveguide technique, has been proposed. detailed explanation the efiects that lay basis presented. The particularly accurate and sensitive highly other techniques are inadequate. can be used spectroscopy broad range liquid solid materials, with applications chemical, pharmaceutical food industry, biomedical sciences,...
In spite of widely studied electrodynamic properties dielectric resonators, nowadays there is no information on Q-factors laminar a kind quasioptical resonators assembled as set coaxial disk laminae with certain inter-lamina spacings. The lack the data prevents us from using for measuring electric characteristics surrounding substances which, due to resonator design, have an enhanced coupling resonator. Current research aimed at filling this gap in our knowledge. Difficulties theoretical...
Dual-layer frequency-selective subwavelength grid polarizers on thin-film dielectric substrates are proposed for THz and sub-THz applications. The dual-layer grids possess enhanced (squared) polarizing efficiency at a sequence of discrete frequencies in reflection within extended frequency bands transmission as compared to conventional single grids.
Optical design in the terahertz (THz) waveband suffers from a lack of dedicated software tools for modelling range electromagnetic and quasi-optical propagation conditions encountered typical systems. engineers are forced to use packages written very different wavelength systems there is often confidence results because possible inappropriate underlying physical models. In this paper we describe analytical techniques CAD (MODAL) that developing long-wavelength analysis THz waveband. Our...
We measured millimeter-wave dielectric parameters of magnesium fluoride glass wafers at the room temperature in frequency band 75-110 GHz by applying open resonator technique based on use Bragg structures and related multi-layer assemblies.Through comparison simulated transmission spectra various structures, constant is found as ε = 5.50±0.01.The estimate for loss tangent to be tan δ 0.00005, with a possibility that actual losses could smaller than this value.