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Santosh Kumar Jha
2015 Journal of Technological Advances and Scientific Research  
Infrared and mm waves have become very useful for night vision equipments, heat seeking missiles, molecular spectroscopy and infrared astronomy. Among other things the trapping of infrared radiations by atmospheric gases is also the basis of green house effects. In infrared astronomy, we make study of astronomical objects by observing infrared radiations they emit. Such celestial bodies can not be seen from the earth, because they do not emit much visible light or that light is blocked by dust
more » ... is blocked by dust and cloud, which infrared radiation can penetrate. Thus infrared and mm wave devices have become a challenging issue in the coming time. So it becomes the duty of each and every science loving scholar to add a step in this direction. INTRODUCTION: The resistive sensor for high power microwave pulse measurement can be devised to study as IR and mm wave devices and applications in the new millennium. [1] The general demand for sensors has grown with the automatization of industrial processes. Many of the new measurement problems have been solved by various kinds of microwave sensors. Microwave sensors are used for a wide range of applications (1) measurement of distance, (2) movement, shape, and (3) particle size, but the largest group of applications are related to measurement of material properties. [2] For the sake of clarity, the word "microwave" must be defined here. It has not been defined exactly in the literature, in the same way as, for example, the acronym UHF, which denotes frequencies in the range 300-3000MHz. It is generally agreed that the wavelength is more significant than the frequency in relation to the word. The American Heritage Dictionary says "Microwave n." An electromagnetic wave having a wavelength in the approximate range from 1mm to 1m, the region between infrared and short-wave radio wavelengths. In this paper the word "Microwave" will be used in cases, where the wavelength is of the same order of magnitude as the measuring device. This is significant, when the interest about RF and microwave sensors for the measurement of dielectric properties of materials during industrial process has been growing recently. Microwave sensors are particularly attractive for their ability of performing non-invasive measurements. An interesting field of application is the real-time moisture measurement during industrial processes, A smart active sensor for measuring the moisture content of felts used in the paper milling industry and more generally of sheet-like materials, is here proposed, The sensor consists of cavity backed slot resonator interacting with the material under test through near fields. The design aspects of the sensor and the related measuring front end are discussed with respect to the dielectric properties of the material, and to the resonator response. The parametric sensitivity of the measuring method with the distance between the sample and the sensor surface and the sample thickness is also analyzed. An inversion procedure based on an Artificial Neural Network (ANN) approach is proposed in order to determine the moisture content of
doi:10.14260/jtasr/2015/21 fatcat:dmj2fkl4kzaqvb7ig3hwo44v5m