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A dual metasurface‐based wideband antenna is proposed herein. The antenna is fed through the stepped aperture of a coplanar waveguide. One layer of the metasurface is printed directly above the aperture, where the other layer is printed on the dielectric plate and placed above the antenna. The antenna bandwidth is significantly improved by the high‐order modes excited by the double‐layer metasurface. The proposed antenna is simple and compact. The − 10 dB relative impedance bandwidth of the proposed antenna is approximately 95.6% (4.8–13.6 GHz), and the main radiation direction deviates from the normal direction by 30°. The proposed antenna has an ultra‐wideband (UWB), which facilitates short‐range indoor UWB positioning. [ABSTRACT FROM AUTHOR]

The High‐Dynamic enhanced Loran (eLoran) signal simulator must accurately model the motion parameters and dynamic transmission delays of the carriers in the channel. A method was proposed based on B‐Spline interpolation, capable of arbitrary ratio interpolation and multi‐channel simulation. This method can regenerate carrier‐to‐transmitter distances from available discrete motion asynchronous data, it can effectively reproduce more motion details for carrier. The algorithm can be implemented using digital circuits, allowing for real‐time simulation on a hardware platform. The circuit structure is divided into integer and fractional calculations, which can satisfy the interpolation of asynchronous data with arbitrary ratios. Compared with existing methods, the approach simulates the motion parameters with satisfactory accuracy. [ABSTRACT FROM AUTHOR]

A model of the LOng‐RAnge Navigation signal can provide a mathematical model for the development of related technology research. The propagation variations of the signal exhibit non‐stationary and non‐linear characteristics due to the time‐varying nature of the atmospheric dielectric constant in the channel. A Dirichlet process mixtures method is used by the authors to model the statistical properties of radio wave attenuation, and the Gibbs sampling method is used to flexibly estimate the parameters of the model. The model as a non‐parametric model can be applied to capture the dynamics of time‐varying signals with the parameters being adaptively inferred. A receiver is used as a measurement device to obtain real propagation data to check the performance of the model. Kullback–Leibler Divergence (KL‐Div) was used to evaluate different datasets. The results showed that the model's statistical properties were consistent. Its flexibility allows it to represent complex distributions without prior knowledge. [ABSTRACT FROM AUTHOR]