Related papers: Design and Realization of a Reflectarray Compact A…
Future NASA X-ray Observatories will shed light on a variety of high-energy astrophysical phenomena. Off-plane reflection gratings can be used to provide high throughput and spectral resolution in the 0.3--1.5 keV band, allowing for…
The goal of this thesis was to develop a procedure to optimize the mirror suppression, which reduces the dynamic range of the Fast Fourier Transform spectrometers (FFTS), and implement this procedure in the Field Programmable Gate Array…
The model of the reflector antenna system with focal plane array, low-noise amplifier and beamformer is developed in the work. The beamformer strategy is suggested to reduce the receiving sensitivity ripple inside field of view of the…
The resonant scattering and diffraction beamline P09 at PETRA III is designed for X-ray experiments requiring small beams, energy tunability, variable polarization and high photon flux. It is highly flexible in terms of beam size and offers…
We briefly consider some design aspects of aperture arrays for use in radio astronomy, particularly contrasting the performance of dense and sparse aperture arrays. Recent insights have emerged in the final design phase of LOFAR which…
Ultrathin metasurfaces have recently emerged as promising materials to enable novel, flat optical components and surface-confined, miniature photonic devices. However, experimental realization of high-performance metasurfaces at visible…
We present a methodology for designing metagratings for perfect anomalous refraction, based on multilayered loaded wire arrays. In recent work, it has been shown that such structures can implement perfect anomalous deflection and beam…
We present the design, construction and measurements of the electromagnetic performance of a wideband space beam splitter. The beam splitter is designed to power divide the incident radiation into reflected and transmitted components for…
A resonant photoacoustic cell capable of detecting the traces of gases at an amplitude-modulation regime is represented. The cell is designed so as to minimize the window background for the cell operation at a selected acoustic resonance. A…
We present the antenna design for a radio interferometer, the Arcminute Microkelvin Imager, together with its beam pattern measurement. Our aim was to develop a low-cost system with high aperture efficiency and low ground-spill across the…
A novel layout for a reflective Arrayed Waveguide Grating is presented in this paper. The device consists of one half of a regular AWG where each arm waveguide in the array is terminated with a phase shifter and a Sagnac loop reflector. The…
A design method of programmable transmitarray with independent controls of transmission amplitude and phase is proposed in C-band. The unit cell with cascaded structures mainly consists of four parts, including the receiving antenna,…
The transmitter signals in the fifth generation (5G) wireless networks suffer from significant path loss due to the use of higher frequencies in Sub-6 GHz and millimeter-wave (mmWave) bands. Therefore, beamforming is an essential and…
Energy of propagating electromagnetic waves can be fully absorbed in a thin lossy layer, but only in a narrow frequency band, as follows from the causality principle. On the other hand, it appears that there are no fundamental limitations…
A novel, low-budget, open-air, slant-geometry antenna test range for UHF radiation is presented. It was designed primarily to facilitate variation of the distance between emitter and receiver antennas, but has also the potential for…
Ultrasonic backscatter measurements are widely used for microstructural characterisation. However, in materials containing strong anisotropy and spatial heterogeneity, the interpretation of backscatter signals becomes challenging because…
The diffraction of electromagnetic plane waves by a rectangular grating formed by discrete steps in the interface of a homogeneous, isotropic, linear, negative phase--velocity (negative index) material with free space is studied using the…
A novel design for a compact gamma-ray spectrometer is presented. The proposed system allows for spectroscopy of high-flux multi-MeV gamma-ray beams with MeV energy resolution in a compact design. In its basic configuration, the…
One of the greatest challenges in applying compressive sensing (CS) signal processing techniques to electromagnetic imaging applications is designing a sensing matrix that has good reconstruction capabilities. Compressive reflector antennas…
A high Radio Analog Signal Processing (R-ASP) resolution transmission-type (TT) phaser based on reflection-type (RT) phaser units is introduced, theoretically studied and experimentally demonstrated. It is first shown that RT phasers…