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The use of high permittivity materials on substrates of a microstrip antenna was developed with Bismuth Niobate ceramic doped with vanadium Oxide (BiNbO 4 (V 2 O 5 )) and compared with an antenna of silicon dioxide substrate (SiO 2 ) using Ansys software HFSS and CST Studio. The ceramic antenna has -20 dB at 3.5 GHz and the silicon dioxide antenna -24.7 dB of reflection coefficient. The bandwidth values are 80 MHz for the bismuth ceramic antenna and 100 MHz for the silica antenna. The results demonstrate that the proposed BiNbO 4 antenna has great advantage compared to those mentioned in terms of volume reduction, presenting results similar to those antennas with higher volume. In addition, we use copper periodic structures (EBG) in order to increase the gain in associated with the use of BiNbO 4 with addition of V 2 O 5 on the antenna substrate leading to a reduction in the total volume. Therefore, the proposed Bismuth Niobate antenna proves to be an excellent alternative for 5G technology and microwave S band (2-4 GHz) devices, highlighting the mentioned advantages.

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In this paper we investigate the performance of a Fiber Bragg Grating (FBG) as a strain-optic and temperature sensor, using the Coupled Mode Theory (CMT) and the Transfer Matrix Method (TMM), through numerical simulation in an interrogation system with Single-Mode Fiber (SMF) and Photonic Crystal Fiber (PCF). Parameters such as sensitivity, bandwidth, peak power, peak wavelength and side-lobes power, were analyzed through the Bragg wavelength change depending on the simultaneous variation of strain and temperature. The FBG sensor proposed suffered thermal variation 25 °C to 200 °C and of strain of 0 μs to 1000 μs, excellent linearity was obtained for the variation of the Bragg wavelength with differences of 0.7 nm for each 50 °C and 0.245 nm for each 200.

In this work, we propose a fiber optic point dendrometer with two Fiber Bragg Grating (FBG) sensors capable of simultaneously measuring strain and temperature considered suitable for monitoring the growth of the diameter of trees in the Amazon compared to conventional electrical sensors and we perform a simulation on the performance of the sensors for measuring the diameter using the Coupled Mode Theory (CMT) and the Transfer Matrix Method (TMM). A measure of the diameter variation was suggested and the sensitivity of the sensors were analyzed from the measurements of the displacements of the Bragg wavelengths varying simultaneously the strain and the temperature. The results showed that the proposed configuration, thermally varied from 0 °C to 80 °C and deformed from 0 to 2400 μ could specifically detect minute variations in diameters with a resolution of 0.5 μm (0.0005 mm) with good linearity staying with a variation of the Bragg wavelength 0.12 nm for each 10 °C and 0.24 nm for each 200 μ. The feasibility of using this type of configuration of FBG sensors for strain and temperature measurements in the monitoring of forest, forestry, climate change and irrigation areas in the Amazon is very promising.

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