Effective path lengths are obtained from experimental measurements of rain attenuation and rain rate at a tropical location

Greater variability of effective path length for stratiform and lesser variability for convective rain are not reflected in ITU-R model

Proposed effective path length models for two rain types provide better agreement with attenuation measurements compared to ITU-R model

The states of the end device after a packet transmission have an important impact on its energy consumption

Acknowledging packets increases the power consumption of an end device and should be taken into account when assessing its power consumption

This paper presents the design of an Ultra-wide band-stop Frequency Selective Surface (FSS)

The proposed FSS design offers band-stop characteristics over the entire UWB operating bandwidth

The proposed FSS is a promising candidate for a multitude of applications such as spatial filtering, antenna gain enhancement

In this paper, the gain and bandwidth of the microstrip antenna with a patch in the form of Antipodal Vivaldi are improved by using log-periodic structures

Three 8-element log-periodic structures designed in a straight-line, U-shaped and V-shaped are proposed, simulated and fabricated

The results of the measurements show that the bandwidth of the 8-element straight-line, U-shaped and V-shaped antennas are 3–18, 2.6–18, and 2.4–18 GHz respectively, and their maximum gain are 6.26, 8.3, and 7.61 dBi, respectively, which has increased the bandwidth by approximately 125% compared to the single element mode and increased the gain from 2.26 to 4.3 dBi

The amplitude and spatio-temporal extent of ionospheric variabilities are quantified across altitude, local time, season, and solar cycle

A method to add these variations into a smooth model is demonstrated and replicates ionospheric data well

This noisy truth model enables more accurate Observation System Simulation Experiments

This paper proposes Huygens sources antennas integrated with partially reflective surfaces for a dual-band operation and gain enhancement

The antenna structure can be operated at two frequency bands with a uni-direction radiation pattern

Classification of spherical objects is achieved by using preprocessed data from the singularity expansion method (SEM)

The residues allow to determine the position of the antenna relative to an object

SEM data provide good noise robustness, high classification accuracy, and excellent generalization to any object size

We use the axisymmetric character of conical horns and some lenses to employ higher-order curved hybrid finite elements

Projecting the problem to a bidimensional mesh, the computational time is drastically reduced and the optimization of the device results much more efficient

Following this approach, we obtain a procedure to reduce the size of very long antennas by adding double convex lenses and dielectric cores; ultra-shortened horns, of a size as small as one wavelength, can then be achieved

A customized real-time weather forecast system is developed for the Deep Space Network tracking sites using a machine learning method

90% of the 24-hr forecasted atmospheric noise temperature has root-mean-squared-error less than 3.50 K

Up to 75% more data can be realized for Ka-band communications links using the real-time weather forecast system