RCS Enhancement of Dielectric Resonator Tag Using Spherical Lens

Abstract The RCS of flat cylindrical Dielectric Resonators (DR) is investigated and found to be too low for an application of the resonators as tags in a novel indoor localization system at mm-wave frequencies. As a method to increase the RCS of a DR tag, we propose the combination with a constant-index spherical lens. The collimation and scattering properties of this lens type are found suitable for a combination with DRs. The optimum relative permittivity of the lens is found in the range of ϵr=1.6 to 2.8 and the optimum distance between lens surface and DR is found slightly larger than the radius of the DR. RCS enhancement is found to vary with the modes of the DR but increases approximately with the fourth power of the lens radius. However, RCS signatures become corrupted by scattering due to mismatch effects of large lenses such that the lens diameter has to be limited to 4 to 5 wavelengths with the RCS enhancement limited to about 30 to 35 dB. Simulation and experimental verification are performed at a down-scaled frequency range from 4 GHz to 7 GHz using lenses of 60 mm and 120 mm diameter made of paraffin wax.

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ZnO-Nb2O5-TiO2 Dielectric Resonators and Porosity Influence on Dielectric Constant Values

Materials Science Forum ◽

10.4028/www.scientific.net/msf.820.193 ◽

2015 ◽

Vol 820 ◽

pp. 193-198

Author(s):

M.C.A. Nono ◽

Pedro José Castro ◽

E.G.L. Rangel ◽

S.L. Mineiro

Keyword(s):

Dielectric Constant ◽

Dielectric Resonator ◽

Chemical Compounds ◽

Microwave Frequency ◽

Dielectric Resonators ◽

Electronic Circuits ◽

Frequency Range ◽

Ceramic Component ◽

Microstructure Characteristics

The dielectric resonator (DR) is a ceramic component used in electronic circuits that can operate in microwave frequency range, where it plays the role of resonant element and enables the construction of high selective filters and oscillators. The dielectric properties of a ceramic resonator are influenced by their microstructure characteristics as pores amount. This work shows a study of the influence of pores amount (porosity) on the dielectric constant values of ceramics from ZnO-Nb2O5-TiO2 system. Mixtures of Nb2O5, ZnO, and TiO2 powders were compacted by uniaxial (100 MPa) and isostatic (300 MPa) pressing and sintered at 1100, 1200, and 1250°C. The experimental dielectric constant values of the sintered ceramics were corrected to eliminate the porosity influence. The results showed that the porosity, the type and quantities of crystalline chemical compounds in the ceramics influence the dielectric constant values.

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Design of a Bell-Shaped Ultra Wideband Antenna for Indoor Localization System

International Journal on Communications Antenna and Propagation (IRECAP) ◽

10.15866/irecap.v5i6.7666 ◽

2015 ◽

Vol 5 (6) ◽

pp. 323 ◽

Cited By ~ 1

Author(s):

Nadia Ghariani ◽

Mohamed Salah Karoui ◽

Mondher Chaoui ◽

Mongi Lahiani ◽

Hamadi Ghariani

Keyword(s):

Indoor Localization ◽

Ultra Wideband ◽

Localization System ◽

Wideband Antenna

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An Indoor Localization System Using Residual Learning with Channel State Information

Entropy ◽

10.3390/e23050574 ◽

2021 ◽

Vol 23 (5) ◽

pp. 574

Author(s):

Chendong Xu ◽

Weigang Wang ◽

Yunwei Zhang ◽

Jie Qin ◽

Shujuan Yu ◽

...

Keyword(s):

Channel State Information ◽

Indoor Environment ◽

Indoor Localization ◽

Location Based Services ◽

Channel State ◽

State Information ◽

Localization Accuracy ◽

Localization System ◽

Increasing Demand ◽

Degradation Problem

With the increasing demand of location-based services, neural network (NN)-based intelligent indoor localization has attracted great interest due to its high localization accuracy. However, deep NNs are usually affected by degradation and gradient vanishing. To fill this gap, we propose a novel indoor localization system, including denoising NN and residual network (ResNet), to predict the location of moving object by the channel state information (CSI). In the ResNet, to prevent overfitting, we replace all the residual blocks by the stochastic residual blocks. Specially, we explore the long-range stochastic shortcut connection (LRSSC) to solve the degradation problem and gradient vanishing. To obtain a large receptive field without losing information, we leverage the dilated convolution at the rear of the ResNet. Experimental results are presented to confirm that our system outperforms state-of-the-art methods in a representative indoor environment.

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