This article describes the effect of the weather on radio wave propagation in a mobile telecommunication network. The research is focused on urban and countryside environments where a correlation between the received signal power level and weather conditions is found using the Random Forest algorithm as a signal level approximator. The results achieved in this paper clearly indicate that it is possible to predict the behaviour of the received power level in relationship to atmospheric phenomena.

This paper introduces an improved shape of Antipodal Vivaldi Antenna from the normal schematic structure which yields a high radiation gain. We have designed and fabricated the improved structure of Antipodal Vivaldi Antenna with the help of new dielectric substrate ASTRA®MT77 material. We have chosen a unique substrate material to develop our novel Antipodal Vivaldi Antenna because most research has been done on commonly used materials like FR4, RT Duroid, etc. Moreover, ISOLA has significantly good electrical and nonelectrical properties as compared with other substrate materials. The results of the desired antenna were simulated through extensive simulations performed in CST Microwave Studio®. The characteristics of all the antenna parameters are clearly studied and we are successful to achieve closed results between designed as well as experimented Vivaldi Antenna. The simulated antenna achieved a maximum gain of more than 9 dBi whereas the experimental antenna reached around 7 dBi between the operating frequency range from 1 GHz to 13 GHz. The measured prototype antenna provides linear polarization with overall radiation efficiency of more than 90%.

This article describes a fiber-optic interferometric sensor and measuring scheme including input-output components for traffic density monitoring. The proposed measuring system is based on the interference in optical fibers. The sensor, based on the Mach-Zehnder interferometer, is constructed to detect vibration and acoustic responses caused by vehicles moving around the sensor. The presented solution is based on the use of single-mode optical fibers (G.652.D and G.653) with wavelength of 1550 nm and laser source with output power of 1 mW. The benefit of this solution lies in electromagnetic interference immunity and simple implementation because the sensor does not need to be installed destructively into the roadway and railroad tracks. The measuring system was tested in real traffic and is characterized by detection success of 99.27% in the case of automotive traffic and 100% in the case of rail traffic.

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In this paper, two planar Frequency Selective Surfaces (FSS) with dissimilar configurations along with monopole antenna exhibiting dual-band response at 3 GHz and 5.5 GHz is presented. One of the surfaces with two reflectors is reflective at 5.5 GHz and transmissive at 3 GHz, whereas the response is opposite for the FSS in another flat reflector. Accordingly the antenna exhibits directive radiation at both the frequencies, however in two opposite directions. Unit cell of the FSS at 3 GHz is on the order of λ g /11, leading to low-profile design. With different orientations of the reflectors, beamwidths at 3 GHz and 5.5 GHz are different leading to different peak gains of 7.1 dBi and 12.2 dBi respectively. The composite antenna-FSS with a dimension on the order of 1.1λ × 1.1λ × 0.2λ exhibits diverse beam radiation. The radiation at 3 GHz can be used in applications involving wide coverage area, whereas at 5.5 GHz the antenna can be used in applications involving smaller beamwidths such as satellite communication, Ground Penetrating Radar etc.