scholarly journals A Nondestructive Testing Method for the Determination of the Complex Refractive Index Using Ultra Wideband Radar in Industrial Applications

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3161
Author(s):  
Vipin Choudhary ◽  
Daniel Rönnow
Keyword(s):  
Refractive Index ◽  
Complex Refractive Index ◽  
Wide Band ◽  
Solid Wood ◽  
Industrial Applications ◽  
Wood Chips ◽  
Ultra Wideband ◽  
Reflection Measurement ◽  
Wideband Radar ◽  
Frequency Domain Techniques

An ultra-wide band radar reflection measurement technique for industrial applications is introduced. A new method for determining the complex refractive index (or equivalently the relative permittivity) of objects with planar interfaces is presented. The object thickness can also be obtained experimentally. The method is a combination of time and frequency domain techniques. The objects can be finite in size and at a finite distance. The limits in size and distance for the method to be valid are experimentally investigated. The method is relatively insensitive to hardware impairments such as frequency dependence of antennas and analog front end. The method is designed for industrial in-line measurements on objects on conveyor belts. Results are presented for solid wood and wood chips; the complex refractive index is determined in the frequency range 0.5 to 2.0 GHz for the moisture content of 3.6–10% for solid wood and 30–50% for wood chips. Polarimetric measurements are used; wood and wood chips are anisotropic.

scholarly journals Automatic target detection and localization using ultra-wideband radar

2022 ◽  
Vol 12 (2) ◽  
pp. 1695
Author(s):  
Dounia Daghouj ◽  
Marwa Abdellaoui ◽  
Mohammed Fattah ◽  
Said Mazer ◽  
Youness Balboul ◽  
...  
Keyword(s):  
Wide Band ◽  
Ultra Wideband ◽  
Correlation Peak ◽  
Distant Object ◽  
Automatic Target Detection ◽  
Broadband Emission ◽  
Uwb Radar ◽  
Wideband Radar ◽  
Detection And Localization

<span>The pulse ultra-wide band (UWB) radar consists of switching of energy of very short duration in an ultra-broadband emission chain, and the UWB signal emitted is an ultrashort pulse, of the order of nanoseconds, without a carrier. These systems can indicate the presence and distances of a distant object, call a target, and determine its size, shape, speed, and trajectory. In this paper, we present a UWB radar system allowing the detection of the presence of a target and its localization in a road environment based on the principle of correlation of the reflected signal with the reference and the determination of its correlation peak.</span>

scholarly journals A printed lens in antenna’s aperture to improve the performance of UWB-radar system

2021 ◽  
Author(s):  
Vipin Choudhary ◽  
Daniel Rönnow ◽  
Malay Ranjan Tripathy
Keyword(s):  
Signal To Noise Ratio ◽  
Complex Refractive Index ◽  
Wide Band ◽  
Industrial Applications ◽  
Radar System ◽  
Band Frequency ◽  
Planar Substrate ◽  
Radar Applications ◽  
Strip Lines ◽  
Non Destructive

Abstractwe present a printed lens for radar applications. The structure of the presented lens consists of an array of modified micro-strip lines, which is positioned in the antenna’s aperture on the same planar substrate. Simulations show that the gain and directivity increase with the proposed lens in a wide band frequency band. The proposed design is insensitive to rotation of the antenna. This paper focuses on real industrial applications and problems. Further, we show that the lens can be used to improve the object detection ability of an ultrawide band radar system, which is used in industrial applications such as non-destructive monitoring of built-structures and for use in the renovation process. The signal to noise ratio is improved. Furthermore, we show how the microwave lens can also be used to reduce the clutter in applications where the complex refractive index of objects is determined. Further, different simulated results (for different cases) are compared, presented and concluded.

scholarly journals An Accurate and Compact High Power Monocycle Pulse Transmitter for Microwave Ultra-Wideband Radar Sensors with an enhanced SRD model: Applications for Distance Measurement for lossy materials

2019 ◽  
Vol 8 (3) ◽  
pp. 76-82
Author(s):  
Y. Ahajjam ◽  
O. Aghzout ◽  
J. M. Catala-Civera ◽  
F. Peñaranda-Foix ◽  
A. Driouach
Keyword(s):  
High Power ◽  
Wide Band ◽  
High Amplitude ◽  
Ultra Wideband ◽  
Gaussian Pulse ◽  
Pulse Generators ◽  
Radar Sensors ◽  
Output Amplitude ◽  
Wideband Radar ◽  
Lossy Materials

In This paper, a high power sub-nanosecond pulse transmitter for Ultra-wideband radar sensor is presented. The backbone of the generator is considered as a step recovery diode and unique pulse injected into the circuit, which gives rise to an ultra-wide band Gaussian pulse. The transistor driver and transmission line pulse forming the whole network are investigated in detail.  The main purpose of this work is to transform a square waveform signal to a driving pulse with the timing and the amplitude parameters required by the SRD to form an output Gaussian pulse, and then into high monocycle pulses. In simulation aspect, an improved output response is required, in this way a new model of step recovery diode has been proposed as a sharpener circuit. This proposition was applied to increase the rise-time of the pulses. For a good range radar, a high amplitude pulse is indispensable, especially when it comes to penetrate thick lossy materiel.  In order to overcome this challenge, a simple technique and useful solution is introduced to increase the output amplitude of the transmitter. This technique consists to connect the outputs of two identical pulse generators in parallel respecting the restrictions required. The pulse transmitter circuit is completely fabricated using micro-strip structure technology characteristics. Waveforms of the generated monocycle pulses over 10V in amplitude with 3.5 % in overshoot have been obtained. Good agreement has been achieved between measurement and simulation results.

Preparation and Characterization of Polyvinylidene Fluoride/ZrO2-TiO2 Optical Film with Wide Band Gap and High Refractive Index

2013 ◽  
Vol 28 (6) ◽  
pp. 671-676 ◽  
Author(s):  
Yu-Qing ZHANG ◽  
Li-Li ZHAO ◽  
Shi-Long XU ◽  
Chao ZHANG ◽  
Xiao-Ying CHEN ◽  
...  
Keyword(s):  
Refractive Index ◽  
Band Gap ◽  
Polyvinylidene Fluoride ◽  
Wide Band ◽  
High Refractive Index ◽  
Wide Band Gap ◽  
Optical Film

scholarly journals Broadband spectroscopy of astrophysical ice analogues

2019 ◽  
Vol 629 ◽  
pp. A112 ◽  
Author(s):  
B. M. Giuliano ◽  
A. A. Gavdush ◽  
B. Müller ◽  
K. I. Zaytsev ◽  
T. Grassi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Time Domain ◽  
Complex Refractive Index ◽  
Far Infrared ◽  
Infrared Region ◽  
Thz Radiation ◽  
The Real ◽  
Thz Range ◽  
The Time Domain

Context. Reliable, directly measured optical properties of astrophysical ice analogues in the infrared and terahertz (THz) range are missing from the literature. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-infrared region. Aims. Coherent THz radiation allows for direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. Methods. We recorded the time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5 K and annealed to 33 K at different thicknesses. We developed a new algorithm to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. Results. The complex refractive index in the wavelength range 1 mm–150 μm (0.3–2.0 THz) was determined for the studied ice samples, and this index was compared with available data found in the literature. Conclusions. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables us, for the first time, to determine the optical properties of astrophysical ice analogues without using the Kramers–Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground-based facilities as well as future space telescope missions, and we used these data to estimate the opacities of the dust grains in presence of CO ice mantles.

The complex refractive index of dusty plasma

Optik ◽  
2019 ◽  
Vol 194 ◽  
pp. 163078
Author(s):  
Xu Meng ◽  
Chen Yun-yun ◽  
Cui Fen-ping
Keyword(s):  
Refractive Index ◽  
Dusty Plasma ◽  
Complex Refractive Index

scholarly journals Ultra-wideband Radar for Angiography

2020 ◽  
Vol 745 ◽  
pp. 012086
Author(s):  
Abdulhameed Habeeb Alghanimi ◽  
Rashid Ali Fayadh
Keyword(s):  
Ultra Wideband ◽  
Wideband Radar
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