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Fresnel reflection and transmission coefficients are well known for the two idealized cases when the two media are either perfect dielectrics [1] or one is a dielectric and the other is a perfect electric conductor (PEC) [2]. However, such is not the case when either one or both media have loss. In a recent paper, Besieris [3] showed that Canning's criticism [4] of the different approaches to the...
This paper presents an interesting feature of the resonant slotted-waveguide antenna array: the difference pattern at off-center frequencies. Our demonstration uses a 12-element center-fed resonant slot array on rectangular waveguide. The simulation results show that the array produces a sum beam pattern at center frequency, and difference beam patterns at two off-center frequencies (around ±8%)....
Recent advances in the monitoring of the plasmasphere (e.g. the PLASMON FP7-Space project, http://plasmon.elte.hu, Lichtenberger et al., Space Weather Space Clim. 3 2013, A23 DOI: 10.1051/swsc/2013045) http) makes the continuous monitoring of the plasmasphere possible. But this monitoring capability totally depends on natural and sporadic phenomena, preventing systematic monitoring required for operational...
An upgraded version of the TGF and Energetic Thunderstorm Rooftop Array (TETRA-II) consists of an array of BGO scintillators to detect bursts of gamma rays from thunderstorms at ground level in four separate locations: the campus of the University of Puerto Rico at Utuado; the campus of Louisiana State University in Baton Rouge, Louisiana; the Severe Weather Institute and Radar & Lightning Laboratories...
Five-hundred-meter Aperture Spherical radio Telescope (FAST) is a Chinese mega-science project to build the largest single dish radio telescope in Guizhou province, Southwest China. The construction of FAST will involve many kinds of analog and digital electrical equipments. The electrical equipments are potential threat to radio observation due to its ElectroMagnetic Interference (EMI) emission....
Herschel[1] was a spatial submillimetre observatory with spectroscopic and imaging capabilities covering the range from 55 to 671 μm (0.44 to 5.5 THz) partly explored for the first time here. With a primary mirror of 3.28 m (effective diameter) and a surface accuracy better than 6 μm, it will remain the largest telescope launched until the arrival of the James Webb Space Telescope end of 2018. The...
Rainfall measured by Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) is important for studying precipitation distribution in the tropical regions. The ground validation of TRMM PR is difficult because the ground sensing systems have different characteristics from TRMM PR in terms of resolution, scale, view aspect and sensing environments. In this paper, we introduce a machine learning...
This paper presents a summary of the project: “Q/V band earth segment Link for Future high Throughput space systems” (QV-LIFT), recently funded in the framework of the EU program Horizon 2020. The project aims at developing up to date hardware and software technologies for the Ground Segment of the future Q/V band terabit Satcom infrastructure.
This presentation will discuss the manner how electro-dynamic and scattering effects can be incorporated into quasistatic-based mixing rules and homogenization principles, thus extending their range of applicability into higher frequencies.
About 15 years ago scientific press began to report about the development of solid-state microwave and ultra-wideband electric-optical and optic-electronic devices, and the number of open publications has increased considerably. Accumulated during this period information allows us to make an assumption about the development of essentially new areas in Radio Engineering, that are called photonics,...
The calibration of the transresistance gain of low-current dc amplifiers can be performed with the capacitance-charging method, where the calibration current is generated by a calibrated voltage ramp applied to a reference capacitor. The method is typically implemented with a purposely-built voltage source having a very low-frequency trapezoidal periodic waveform output. Here we propose a variation...
A long-standing question in lightning studies has concerned how lightning is initiated in thunderstorms, given the absence of physical conductors. Remote sensing observations of discharges are starting to provide the answer to this question, obtained in large part with radio frequency instruments and techniques. A recent important and unexpected step in this process has come from observations of the...
In this paper, an integrated solution based on passive UHF RFID tag sensor is proposed to measure the pressure on different types of sports balls. A comparison of two commercial piezzoresistive sensors based on different technologies is performed for this type of pressure measurement application. Several external sensor interface chip configurations (SFE) have been tested and adapted to the resistance...
An asymmetrical double ridge waveguide is used to develop power splitter/combiner with arbitrary power division ratio. The power splitter is inherently wide band covering the whole band of the waveguides. The splitter can have a very short length and needs the same width as the input waveguide. It has a highly constant coupling value with return loss better than 25 dB. Results of a 10-dB power splitter...
The SKA South Africa radio astronomy roadmap is in 4 phases: Phase 1: construction of the pathfinder KAT-7 (7 × 12m antennae) completed in December 2010 & in operation since then (8 HI scientific publications — description of the results to follow); Phase 2: construction of the SKA precursor MeerKAT (maximum baseline ∼8 km) (64 × 13.5m antennae), fully funded (RSA), completed in mid-2018; Phase...
To explore the possible non-thermal biological effects of intermediate frequency magnetic field (IF-MF) on mice, we developed exposure apparatus using 85 kHz time-varying magnetic field and examined the effects on oxidative stress by subacute and acute exposure conditions. Our data showed no effect on oxidative stress under the exposure condition, which approximately corresponds to the basic restriction...
The NASA dual-frequency, dual-polarization, Doppler radar (D3R) [1] was conceived and developed to support ground validation (GV) operations of the Global Precipitation Measurement (GPM) mission [2]. The D3R operates in the same frequencies bands, Ku- and Ka-band, as GPM's dual-frequency precipitation radar enabling direct comparisons of microphysical observations of precipitation. To support the...
We present the general features and aspects regarding the electromagnetic scattering by a small core-shell sphere. First, the thickness effects on the plasmonic resonances are described in the Rayleigh limit, utilizing the MacLaurin expansion of the Mie coefficients of hollow scatterers. The results are connected with the plasmon hybridization model. A brief study regarding the core effects is given,...
This paper summarizes and elaborates on some new results on the optimal absorption in small spherical suspensions based on electrophoretic (plasmonic) resonances and lossy surrounding media. The main application here is to study the physical limitations for radio frequency absorption in gold nanoparticle (GNP) suspensions and its potential to achieve GNP targeted hyperthermia in cancer therapy. Numerical...
The acceleration of charged particles to high energies is a common, though poorly understood, process in natural plasmas. In the astrophysical domain the heliosphere offers particularly favorable conditions for its study because of the proximity of the observer to the acceleration sites and the ensuing possibility to observe radiative signatures with spatial and temporal resolution, and to combine...
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