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Issue Information

  •  8 April 2021
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Thank You to Our 2020 Reviewers

  •  18 March 2021

Key Point

  • The editors thank the 2020 peer reviewers

Modeling Center‐of‐Mass of the Ionosphere From the Slab‐Thickness

  •  12 March 2021

Key Points

  • Center‐of‐mass of ionosphere Hc is derived from Ne(h) and TEC(h) profiles at the slab‐thickness t range between hmF2‐tbot and hmF2+ttop

  • Center‐of‐mass Hc obtained with IRI‐Plas and NeQuick models is proposed as varying shell height for conversion of sTEC to vTEC

  • Center‐of‐mass Hc is modeled as linear function of hmF2 for 6 longitudinal zones and the relevant regression coefficients are provided

RF Energy Harvesting Using High Impedance Asymmetric Antenna Array Without Impedance Matching Network

  •  7 March 2021

Key Points

  • This paper has proposed a 2.45 GHz rectenna with a high impedance asymmetric antenna array without the using of any matching network

  • The proposed rectenna has attained over than 60% RF‐DC conversion efficiency at a single frequency band with a wide load impedance range

  • The proposed design is suitable for high efficiency wireless power transfer and wireless energy harvesting applications, because of good performance

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Determination of the Azimuthal Extent of Coherent E‐Region Scatter Using the ICEBEAR Linear Receiver Array

  •  7 March 2021

Key Points

  • A method to determine the azimuthal angle of arrival and azimuthal extent of E‐region coherent scatter was developed for the Ionospheric Continuous‐wave E‐region Bistatic Experimental Auroral Radar (ICEBEAR)

  • The azimuthal angle and extent of targets were found using Gaussian fits to cross‐spectra coherence data from a linear receiving array

  • Data from ICEBEAR in the linear receiving array configuration can use this imaging method to accurately map the data

Refractivity‐From‐Clutter Capable, Software‐Defined, Coherent‐on‐Receive Marine Radar

  •  26 February 2021

Key Points

  • A refractivity from clutter capable software defined coherent on receive radar is built and demonstrated

  • Refractivity from clutter can be performed with a low‐cost commercial off the shelf marine radar system with proper modifications

  • Noise calibration and coherence can be established for a low‐cost marine radar system in post‐processing

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Issue Information

  •  25 February 2021
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Issue Information

  •  9 February 2021

A Review on Different Techniques of Mutual Coupling Reduction Between Elements of Any MIMO Antenna. Part 2: Metamaterials and Many More

  •  8 February 2021

Key Points

  • Mutual coupling (MC) reduction among antenna elements is a significant challenge while designing a compact MIMO antenna design

  • The negative permittivity and permeability property of Metamaterials helps in suppressing the ground wave propagation

  • Some more MC reduction techniques have been discussed thoroughly in this article, like Electromagnetic Band Gap (EBG) structure, Decoupling and Matching network, and Neutralization line

A Review on Different Techniques of Mutual Coupling Reduction Between Elements of Any MIMO Antenna. Part 1: DGSs and Parasitic Structures

  •  4 February 2021

Key Points

  • Multiple‐Input‐Multiple‐Output (MIMO) patch antenna is required for high data rate transmission without additional bandwidth requirement

  • Mutual coupling reduction among antenna elements is a significant challenge while designing a compact antenna array system

  • Defected Ground Structures and Parasitics elements/structures for mutual coupling reduction have been discussed thoroughly in this article

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Evaluation of an antenna selection strategy for reduced massive MIMO complexity

  •  7 March 2021

Key Points

  • Reduced massive MIMO complexity using Rx spatial correlation for antenna selection strategy. Results show good results with less RF chains.

  • A proposed optimization algorithm for the number of active Tx antennas with a dynamic number of users and different correlation targets.

  • Main results demonstrate that wisely selecting a number of antennas using the selection algorithm, performs very well compared to full array. Experimental results in an industrial scenario support these claims.

Impact of the propagation model on the capacity in small‐cell networks: comparison between the UHF/SHF and the millimetre wavebands

  •  1 February 2021

Key Points

  • Urban/vehicular, pedestrian, urban micro and modified Friis propagation models have been considered for the UHF/SHF and millimetre wavebands.

  • In the linear and Manhattan grid topologies, for short cell sizes, the supported throughput, which is mapped to the signal‐to‐interference‐plus‐noise ratio, is higher at the millimetre wavebands compared to the UHF/SHF bands.

  • In the UHF/SHF band, for larger cell sizes/radius, all of the models are similar, but for shorter cell sizes, the number of needed pico cells is underestimated if the two‐slope propagation model is considered instead of a single‐slope model.

Impact of the ionosphere disturbed by rocket plume on OTHR radio wave propagation

  •  27 January 2021

Key Points

  • Three‐dimensional ray tracing is adopted to simulate propagation paths of radio waves, which propagate through ionospheric hole at different release times.

  • The absorption loss at high solar activity is significantly higher than that at low solar activity, which is strongest in summer and weakest in winter.

  • Radio waves at 10, 15, and 20 MHz can all pass through “ionospheric hole” area, and most of 8 MHz rays are reflected to the ground.

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Statistics of total electron content depletions observed over the South American continent for the year 2008

Key Points

  • First time regional plots of TEC depletions
  • New numerical algorithm developed to automatically detect TEC depletions
  • Day‐to‐day variability of TEC depletions in a regional basis

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Relative detection efficiency of the World Wide Lightning Location Network

Key Points

  • A relative detection efficiency model for the WWLLN is developed
  • The model is used to analyze current and past network performance
  • The performance effects of a single station outage are examined

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On the reliability of the Spatial Scintillation Index to detect earthquake precursors in the ionosphere

Key Points

  • We discuss the SSI index as indicator of earthquakes precursors
  • We show that SSI preearthquake changes may be explained as geomagnetic effects
  • We show that SSI is not reliable indicator of precursory effects of earthquakes

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Digital transmission techniques for a long haul HF link: DSSS versus OFDM

Key Points

  • Advanced modulation techniques applied to HF communications
  • Spread spectrum and OFDM modulations for ionospheric transmissions

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Accurate measurements of the dielectric constant of seawater at L band

Key Points

  • Dielectric measurements of seawater are made with a microwave cavity at 1.413 GHz
  • Measurements are made as a function of temperature and salinity for values found in open ocean
  • Accuracy is better than 0.3 for both real and imaginary parts of the dielectric constant

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An Indoor Path Loss Prediction Model Using Wall Correction Factors for Wireless Local Area Network and 5G Indoor Networks

Key Points

  • A modified effective wall loss model (EWLM) for indoor environment is presented
  • Real‐time measurements and simulations for various indoor path loss models are used
  • Several frequency spectrum band were considered for evaluation purposes

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Measurement of Ionospheric Total Electron Content Using Single‐Frequency Geostationary Satellite Observations

Key Points

  • The derivation of total electron content using single‐frequency terrestrial GPS receivers and geostationary satellites is demonstrated
  • The demonstrated technique is validated by correlation analysis
  • The correlations between TEC time series for pairs of receivers and between receivers and an ionosonde over a year show good agreement

Plain Language Summary

The ionized upper portion of the atmosphere is known as the ionosphere. The ionosphere interferes with signals traveling between satellites and the ground and can cause errors in satellite navigation, surveillance, and communication systems. The impact of these errors can be reduced if we are able to measure the total electron content (TEC), which can be simply thought of as the total number of electrons in a straight line between a satellite and the ground. We have developed a technique that allows us to measure TEC using receivers measuring single‐frequency signals from geostationary satellites. This is useful because it will increase the number of measurements available and because using geostationary satellites makes the measurements relatively easy to interpret. To test the technique we use a correlation analysis to compare measurements made by the single‐frequency receivers. We also correlate technique measurements with independent TEC observations made by an ionosonde. All correlation results showed good agreement, suggesting consistency for the technique, and that the technique is reliable. The demonstrated technique has the potential to become a routine method to derive TEC, which will help to map the ionosphere in real time.

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A focusing reflectarray and its application in microwave virus sanitizer

Key Points

  • A focusing reflectarray is proposed for use in microwave virus sanitizer
  • Design details of the proposed focusing reflectarray are discussed
  • An 8 GHz prototype design is fabricated, and its feasibility is also verified

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Ray tracing propagation modeling for future small‐cell and indoor applications: A review of current techniques

Key Points

  • Ray tracing modeling can provide reliable channel characterization
  • Proper modeling of the diffuse scattering is crucial to get good results

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