Related papers: Confocal Ellipsoidal Reflectors with Phased Array …
Phase delays, spectral, orientation, and angular dependences of radiation refraction in metamaterial targets have been experimentally studied within the millimeter-wave range. It has been shown that angular and spectral dependences have a…
This paper presents the design of a new dual-polarised Vivaldi feed for the Hydrogen Epoch of Reionization Array (HERA) radio-telescope. This wideband feed has been developed to replace the Phase I dipole feed, and is used to illuminate a…
The RISTRETTO project is aiming to build an instrument that will detect the reflected light from close-by exoplanet. It is a two stage instrument: An extreme AO system in the visible, followed by a seven spaxel single mode High resolution…
Spatio-spectral selectivity, the capability to select a single mode with a specific wavevector (angle) and wavelength, is imperative for light emission and imaging. Continuous band dispersion of a conventional periodic structure, however,…
We experimentally demonstrate how to solve the phase problem of diffraction using multi-wave interference with standard diffraction experimental setups without the need for taking any auxiliary data. In particular, we show that the phases…
In millimeter wave (mmWave) systems, the advanced lens antenna array can effectively reduce the radio frequency chains cost. However, the mmWave signal is still vulnerable to blocking obstacles and suffers from severe path loss. To address…
Wearable on-body millimeter-wave (mmWave) radars can provide obstacle detection and guidance for visually impaired individuals. The antennas, being a crucial component of these systems, must be lightweight, flexible, low-cost, and compact.…
A new X-band leaky-wave antenna has been developed using spin photonic topological insulators. This antenna features a hexagonal unit cell arranged in an armchair configuration. This arrangement provides advantages over the zigzag…
Blindly estimating the direction of arrival (DoA) of early room reflections without prior knowledge of the room impulse response or source signal is highly valuable in audio signal processing applications. The FF-PHALCOR (Frequency Focusing…
This paper considers the question of characterizing the behavior of waves reflected by a fractional singularity of the wave speed profile, i.e., of the form \[ c(x_1, x_2, x_3) = c_0 \left(1 + \left( \frac{x_1}{\ell}\right)_{+}^\alpha…
A resonant two level atom doped in one dimensional waveguide behaves as a mirror, but this single-atom "mirror" can only reflect single photon perfectly at a specific frequency. For a one dimensional coupled-resonator waveguide, we propose…
This article present a new method to reconstruct slowly varying width defects in 2D waveguides using one-side section measurements at locally resonant frequencies. At these frequencies, locally resonant modes propagate in the waveguide up…
This paper is dedicated to design a direct sampling method of inverse electromagnetic scattering problems, which uses multi-frequency sparse backscattering far field data for reconstructing the boundary of perfectly conducting obstacles. We…
Using concave rectangular patches, a new solution to reduce mutual coupling and return loss in two-dimensional array of microstrip antennas is proposed. The effect of width and length concavity on mutual coupling and return loss is studied.…
Virtually imaged phased array (VIPA) spectrometers provide high resolution and fast acquisition in a compact design, but their performance as dispersive instruments is sensitive to fabrication tolerances, component dimensions, and…
A proof of concept for high speed near-field imaging with sub-wavelength resolution using SLM is presented. An 8 channel THz detector array antenna with an electrode gap of 100 um and length of 5 mm is fabricated using the commercially…
We present a compact two-lens HDPE f/1.6 refractor design that is capable of supporting a 28-deg diffraction-limited field of view at 1-mm wavelengths and contrast it to a similar two-lens refractor using silicon lenses. We compare the…
High-frequency communication systems bring extremely large aperture arrays (ELAA) and large bandwidths, integrating localization and (bi-static) sensing functions without extra infrastructure. Such systems are likely to operate in the…
Flexible-geometry arrays have garnered much attention in wireless communications, which dynamically adjust wireless channels to improve the system performance. In this paper, we propose a novel flexible-geometry array for a $360^\circ$…
Applying numerical modeling coupled with experiments, we investigate the properties of wideband resonant reflectors under fully conical light incidence. We show that the wave vectors pertinent to resonant first-order diffraction under fully…