A Ku-Band Compact Offset Cylindrical Reflector Antenna with High Gain for Low-Earth Orbit Sensing Applications.

The rise of CubeSats has unlocked opportunities for cutting-edge space missions with reduced costs and accelerated development timelines. CubeSats necessitate a high-gain antenna that can fit within a tightly confined space. This paper is primarily concerned with designing a compact Ku-band offset cylindrical reflector antenna for a CubeSat-based Earth Observation mission, with the goal of monitoring Arctic snow and sea ice.

Dual-band millimetre wave MIMO antenna with reduced mutual coupling based on optimized parasitic structure and ground modification.

In this study, a high-isolation dual-band (28/38 GHz) multiple-input-multiple-output (MIMO) antenna for 5G millimeter-wave indoor applications is presented. The antenna consists of two interconnected patches. The primary patch is connected to the inset feed, while the secondary patch is arc-shaped and positioned over the main patch, opposite to the feed.

Gain and Bandwidth Enhancement of 3D-Printed Short Backfire Antennas Using Rim Flaring and Iris Matching.

In this article, we present new design techniques to improve the gain and impedance bandwidth of short backfire antennas. For the gain enhancement procedure, our approach was to flare the rim of the antenna, which simultaneously led to an increase in the impedance bandwidth of the antenna. Parametric studies were carried out to obtain the optimal flaring angle.

wideband high-gain low-profile series-fed antenna integrated with optimized metamaterials for 5G millimeter wave applications.

This paper presents a series-fed four-dipole antenna with a broad bandwidth, high gain, and compact size for 5G millimeter wave (mm-wave) applications. The single dipole antenna provides a maximum gain of 6.2 dBi within its operational bandwidth, which ranges from 25.

Mass Reduction Techniques for Short Backfire Antennas: Additive Manufacturing and Structural Perforations.

This paper presents novel approaches for reducing the mass of the classical short backfire (SBF) antenna by using additive manufacturing and structural perforations. We first investigated techniques to create a 3D-printed structure with a conductive coating material. This approach resulted in a significant mass reduction (70%) compared with the conventional metallic structure.

Gain Enhancement and Cross-Polarization Suppression of Cavity-Backed Antennas Using a Flared Ground Cavity and Iris.

Herein, we present new design principles for gain enhancement and cross-polarization suppression in dual-polarized cavity-backed antennas and demonstrate the capability in an octagonal cavity-backed open prism antenna (OCROP). In our approach, the gain is enhanced through an optimal flaring procedure and a novel metallic iris is used to control the electromagnetic fields and thereby reduce the cross-polarization. Previously, we investigated a dual-polarized OCROP antenna configuration and were able to simultaneously achieve 50% impedance bandwidth, 40% cross-polarization bandwidth (≤25 dB), and 10.

Split Ring Antennas and Their Application for Antenna Miniaturization.

This paper investigates the miniaturization capability of split ring array antennas embedded in a low-permittivity dielectric substrate, in comparison with the same-sized high-permittivity dielectric resonator antennas (DRAs). In order to understand the miniaturization performance, a size-fixed dielectric substrate with different split ring arrays is studied. The simulation results show that the miniaturization capability increases with decreased unit cell resonant frequency and/or increased unit cell induced permeability.

Wideband Dual-Polarized Octagonal Cavity-Backed Antenna with Low Cross-Polarization and High Aperture Efficiency.

Simultaneously enhancing multiple antenna performance parameters is a demanding task, especially with a challenging set of design goals. In this paper, by carefully deriving a compatible set of enhancement techniques, we propose a compact/lightweight/low-cost high-performance L-band octagonal cavity-backed hybrid antenna with multiple attractive features: dual-polarization, wide impedance bandwidth, low cross-polarization, high gain, and high aperture efficiency. The ground cavity is octagonal, which allows the antenna to have a small footprint, and, more importantly, low cross-polarization and high aperture efficiencies when compared to a commonly-used square design.

Methods for Interpreting the Partitioning and Fate of Petroleum Hydrocarbons in a Sea Ice Environment.

Decreases in Arctic Sea ice extent and thickness have led to more open ice conditions, encouraging both shipping traffic and oil exploration within the northern Arctic. As a result, the increased potential for accidental releases of crude oil or fuel into the Arctic environment threatens the pristine marine environment, its ecosystem, and local inhabitants. Thus, there is a need to develop a better understanding of oil behavior in a sea ice environment on a microscopic level.

Investigation into the geometry and distribution of oil inclusions in sea ice using non-destructive X-ray microtomography and its implications for remote sensing and mitigation potential.

As climate change brings reduced sea ice cover and longer ice-free summers to the Arctic, northern Canada is experiencing an increase in shipping and industrial activity in this sensitive region. Disappearing sea ice, therefore, makes the Arctic region susceptible to accidental releases of different types of oil and fuel pollution resulting in a pressing need for the development of appropriate scientific knowledge necessary to inform regulatory policy formulation. In this study, we examine the microstructure of the surficial layers of sea ice exposed to oil using X-ray microtomography.

Photooxidation and biodegradation potential of a light crude oil in first-year sea ice.

Disappearing sea ice in the Arctic region results in a pressing need to develop oil spill mitigation techniques suitable for ice-covered waters. The uncertainty around the nature of an oil spill in the Arctic arises from the ice-covered waters and sub-zero temperatures, and how they may influence natural attenuation efficiency. The Sea-ice Environmental Research Facility was used to create a simulated Arctic marine setting.

Effect of dissolution, evaporation, and photooxidation on crude oil chemical composition, dielectric properties and its radar signature in the Arctic environment.

Accidental release of petroleum in the Arctic is of growing concern owing to increases in ship traffic and possible future oil exploration. A crude oil-in-sea ice mesocosm experiment was conducted to identify oil-partitioning trends in sea ice and determine the effect of weathering on crude oil permittivity. The dissolution of the lighter fractions increased with decreasing bulk oil-concentration because of greater oil-brine interface area.

Examining the physical processes of corn oil (medium crude oil surrogate) in sea ice and its resultant effect on complex permittivity and normalized radar cross-section.

Due to the effects of heightened warming in the Arctic, there has been an urgency to develop methods for detecting oil in (or under) sea ice, owing to increasing potential for oil exploration and ship traffic in the more accessible Arctic regions. To test the potential for radar utilizing the normalized radar cross section (NRCS) of the sea ice, an oil-in-ice mesocosm experiment was performed. Throughout the experiment, corn oil was used as a surrogate for medium crude oil, to assess oil movement tendencies in sea ice, and the resultant impact on the complex permittivity through measurement and modelling techniques.

Oil behavior in sea ice: Changes in chemical composition and resultant effect on sea ice dielectrics.

There has been increasing urgency to develop methods for detecting oil in sea ice owing to the effects of climate change in the Arctic. A multidisciplinary study of crude oil behavior in a sea ice environment was conducted at the University of Manitoba during the winter of 2016. In the experiment, medium-light crude oil was injected underneath young sea ice in a mesocosm.