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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]

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]

In this letter, a miniaturized spoof surface plasmon polaritons (SSPPs) low-pass filter with a novel transition structure is proposed. The novel transition structure is designed by two rectangular strips with an inclination of 17° and right-angled triangle patches. In this letter, we analyzed the normal and azimuthal components of the electric field perpendicular to the plane of the filter at different locations, verifying the effectiveness of the transitional structure. Besides, efficient conversion between quasi-transverse electromagnetic (TEM) waves and transverse magnetic (TM) polarized SSPPs waves are achieved by loading the novel transition structures. The designed filter can suppress unnecessary radiation loss and increase transmission efficiency. More importantly, the filter size is 47.52 mm $\times7.47$ mm and its length is reduced by at least 61% compared with the other low-pass filters with the same cutoff frequency. This letter has promoted the development and application of SSPPs low-pass filter and related equipment in microwave frequencies. [ABSTRACT FROM AUTHOR]

In this letter, an ultrawideband (UWB) multiple-input–multiple-output (MIMO) antenna using a novel fence-type decoupling structure, which has high isolation in the UWB, is presented. The MIMO design consists of two half-cutting UWB antenna units that have good low-frequency impedance-matching performance because of the use of a rectangular slot on the radiation patch. Meanwhile, the isolation in the operating band is enhanced by introducing the fence-type decoupling structure at the ground of the antenna. Furthermore, the L-shaped parasitic branches are designed to heighten the impedance bandwidth and isolation in the low-frequency band, i.e., 3–3.4 GHz. The simulation and experiments show that the antenna has low mutual coupling (S21 < –25 dB) and a low envelope correlation coefficient (ECC < 0.004) in the UWB. [ABSTRACT FROM AUTHOR]