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antennae, etc ; couplings; dimensions; microwave radiation; microwave treatment; wavelengths; Show all 6 Subjects
Abstract:
... In this paper, a novel MIMO antenna operating in the UWB frequency band is presented. The proposed new antenna shape is derived from the conventional circular ring patch antenna having a partial ground plane. An array of three Quad-G Shaped Metamaterial structures was used between the antenna elements of the two-port MIMO antenna to expand the bandwidth in the lower frequency band of UWB applicati ...
antennae, etc ; data collection; geometry; remote sensing; synthetic aperture radar; Show all 5 Subjects
Abstract:
... This article investigates channel phase mismatch calibration during the application of displaced-phase-center antenna (DPCA) in dual-channel sliding spotlight synthetic aperture radar (SAR) for ground moving target indication (GMTI). In sliding spotlight SAR, the utilization of beam progressive sweeping in azimuth causes antenna phase centers to be misaligned from the sensor path, resulting in the ...
Shamsul Ammar Shamsul Baharin; Mohd Riduan Ahmad; Taha Raad Khaleel Al-Shaikhli; Muhammad Abu Bakar Sidik; Muhammad Haziq Mohammad Sabri; Ammar Ahmed Nasser Al-Kahtani; Sulaiman Ali Mohammad; Gaopeng Lu; Hongbo Zhang; Vernon Cooray
antennae, etc ; avalanches; duration; electrons; microwave radiation; microwave treatment; research; sampling; stems; Show all 9 Subjects
Abstract:
... In this paper, Very-High Frequency (VHF) and microwave radiation pulses associated with stepped leader pulses (conventional breakdown) are examined. A total of 100 stepped leader pulses (SLPs) with the associated 100 quiet periods (QPs) from ten negative cloud-to-ground (CG) flashes within the reversal distance (<8 km) have been analyzed. The QP is defined as the period between two SLPs when no el ...
antennae, etc ; Earth ionosphere; electrical conductivity; exhibitions; fields; mathematical models; methodology; remote sensing; solutions; surfaces; Show all 10 Subjects
Abstract:
... Fully coupled lithosphere, atmosphere, and ionosphere theory has demonstrated that extremely low-frequency electromagnetic (ELF-EM) fields present a broad application prospect in deep resource exploration, but previous studies have ignored the contribution of the Earth’s curvature. This study extends the theory of ELF-EM over a stratified Earth to the case where the Earth’s curvature must be taken ...
antennae, etc ; data collection; image analysis; remote sensing; research; satellites; synthetic aperture radar; testing; theoretical models; wills; Show all 10 Subjects
Abstract:
... LuTan-1 (LT-1) is an innovative spaceborne radar Earth observation mission including two satellites equipped with synthetic aperture radar (SAR) which will be launched in 2022. Active phased array antennas that can be divided into two physical channels are equipped on each satellite. The signal can be transmitted through the full antenna without broadening and recorded by each channel. Therefore, ...
... We demonstrate here that selective vibrational excitation of a moiety, remotely attached in relation to the molecular reaction site, might offer a generalized strategy for inducing bond-breaking/bond-forming reactions with exquisite precision. As a proof-of-principle, the electrocyclic ring-expansion of a benzazirine to a ketenimine was induced, in a cryogenic matrix, by near-IR light tuned at the ...
antennae, etc ; exhibitions; monitoring; remote sensing; satellites; Show all 5 Subjects
Abstract:
... Following the continuous and stable regional service of BDS2, the BDS3 officially announced its global service in July 2020. To fully take advantage of the new multi-frequency BDS3 signals in ionosphere sensing and positioning, it is essential to understand the characteristics of the differential code bias (DCB) of new BDS3 signals and BDS performance in global ionospheric maps (GIMs) estimation. ...
antennae, etc ; design; dielectrics; fabrics; journals; topology; Show all 6 Subjects
Abstract:
... This paper is devoted to a novel textile ultra-wideband (UWB) antenna for wearable applications. The antenna is designed and implemented on a felt textile substrate with attractive features such as a flexible full embroidered topology and a low dielectric loss. In this study, the UWB antenna is evaluated through the reflection coefficient (S11), gain, efficiency and effects of bending. The UWB ope ...
... While targeting the sixth generation (6G) wireless communication which incorporates mainly the Internet of Things (IoT), the Internet of Vehicles (IoV) becomes a vital component to be implemented. A vehicular antenna is designed by using the modified design of the Vivaldi antenna that can cover all the frequency bands for the long-term evolution (LTE) and the mid-band fifth-generation (5G) wireles ...
... The problem of modelling reflections from targets for radar systems with two receiving antennas with spaced phase centres and overlapping directional patterns is considered. The conditions that must be met by the emitter matrix are obtained, which provides the ability to independently simulate the target in the desired position for each antenna. A configuration of a matrix consisting of five point ...
antennae, etc ; methodology; portable equipment; prototypes; radio; Show all 5 Subjects
Abstract:
... The antenna presented in this work is based on a meandering monopole patch antenna with the incorporated shorting-pin technique for the realization of multiband antenna. The proposed antenna is printed on an FR4 with a footprint of 0.22λg×0.36λg at the lowest operating frequency. The antenna proposed demonstrated six resonances with suitable bandwidth as well as gain which make it suitable for WiM ...
antennae, etc ; communications technology; design; electroplating; fabrics; journals; wavelengths; Show all 7 Subjects
Abstract:
... In this paper, a novel wearable wideband antenna for application in wireless medical communication systems (0.9–6 GHz) is designed. For bandwidth enhancement, five parallel metal plates (PMPs) are placed on the top of the antenna’s patch without any disturbing effects on the performances. With the help of the proposed method, the bandwidth has been increased by about 3 GHz in comparison with the c ...
antennae, etc ; fields; geometry; journals; mathematical models; physical chemistry; wavelengths; Show all 7 Subjects
Abstract:
... Plasmonics, particularly the one based on plasmon resonances in optical antennas for the excitation of localized and enhanced light fields, have enabled numerous nanophotonics applications over the past few decades. One of the most common applications is to generate a nanoscale light source through plasmon resonance. An alternative phenomenon that has recently gained increasing attention for creat ...
antennae, etc ; control methods; design; energy; materials; methodology; prediction; solutions; Show all 8 Subjects
Abstract:
... Phase-gradient metasurfaces (PGMs) constitute an efficient platform for deflection of a beam in a desired direction. According to the generalized Snell’s law, the direction of the reflected/refracted wave can be tuned by the spatial phase function provided by the PGMs. However, most studies on PGM focus only on a single diffraction order, that is, the incident wave can be reflected or refracted to ...
antennae, etc ; filters; image analysis; remote sensing; sampling; system optimization; Show all 6 Subjects
Abstract:
... Imaging systems based on millimeter waves (mm-waves) are advancing to achieve higher resolution and wider bandwidth. However, a large bandwidth requires high sample rates, which may limit the development of ultra-wideband imaging systems. In this letter, we introduce the concept of frequency diverse array (FDA) into mm-wave imaging systems. In particular, we propose an ultra-wideband imaging metho ...
antennae, etc ; clothing; measurement; remote sensing; synthetic aperture radar; topology; Show all 6 Subjects
Abstract:
... In this work, a novel rotation approach for the antenna elements of a linear phased array is presented. The proposed method improves by up to 14 dB the cross-polarization level within the main beam by performing a sequential 90° rotation of the identical array elements, and achieving measured cross-polarization suppressions of 40 dB. This configuration is validated by means of simulation and measu ...
antennae, etc ; geometry; image analysis; interferometry; remote sensing; synthetic aperture radar; Show all 6 Subjects
Abstract:
... Imaging position shift based on the multiple azimuth squint angles (MASA) mode is effective for target azimuth velocity estimation, whereas accuracy is low when target range velocity is high. In this paper, the estimation problem for both target azimuth and range velocities is considered based on the multi-channels MASA (MC-MASA) mode. Firstly, the acquisition geometry of MC-MASA mode and Doppler ...
antennae, etc ; accuracy; algorithms; environment; filters; remote sensing; variance covariance matrix; wheels; Show all 8 Subjects
Abstract:
... The angular position measurement of an array antenna based on a wireless signal has high accuracy in an indoor no-occlusion environment. However, due to the high complexity of indoor environments, signal occlusion, multipath, and other interfering factors are inevitable when users move randomly, which can greatly reduce the positioning accuracy. In addition, different directions of the positioning ...
antennae, etc ; business enterprises; communications technology; detectors; energy efficiency; exhibitions; methodology; solutions; Show all 8 Subjects
Abstract:
... Fifth generation wireless communication system is implemented by several mobile companies where important technologies are employed such as the massive multiple-input multiple-output (MIMO). Although it improves the spectrum and energy efficiencies, it is not a trivial to propose an efficient detector for massive MIMO systems because a large number of antennas increases the computational complexit ...
antennae, etc ; calibration; couplings; exhibitions; field experimentation; latitude; models; remote sensing; robots; solutions; Show all 10 Subjects
Abstract:
... For the same antenna type, numerical differences among the phase center correction (PCC) models released by different institutes can reach several millimeters, which is far beyond the nominal calibration accuracy. This contribution introduces a new method to evaluate the consistency of these PCC models. We first investigated the coupling of phase center offset (PCO) and phase center variation (PCV ...