Banca de QUALIFICAÇÃO: ISAU DE SOUSA SILVA JUNIOR

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ISAU DE SOUSA SILVA JUNIOR
DATE: 15/08/2024
TIME: 14:00
LOCAL: https://meet.google.com/okv-mtxe-gqf
TITLE:

Development of a wide-range soil moisture sensor based on microstrip antenna

KEY WORDS:

Soil moisture sensor, Microwave planar sensor, Soil moisture content, Microstrip antenna, Interdigital capacitor.

PAGES: 66
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUMMARY:

Soil water content and water availability are of fundamental importance for land-based activities, especially those involving agriculture, forestry, hydrology, and engineering. For this reason, several authors have proposed practical and simple ways of obtaining this information using a wide variety of measurement techniques. Of the many techniques for determining soil moisture content, techniques based on dielectric characteristics, such as time domain reflectometry (TDR) and frequency domain reflectometry (FDR), stand out as the most widely used for measuring volumetric soil moisture content in the field. However, despite the good performance of these techniques, the cost of acquiring sensors of this type is quite high, making it impossible to use these devices extensively in the field. In this context, planar microwave sensors have been gaining a lot of attention from researchers as an alternative for sensing soil moisture in the field because, of their inherent characteristics, such as low production cost, ease of handling, lightness, small size, and measurement speed, these sensors are very suitable for applications that require continuous sensing and in large quantities in situ. However, despite the advantages of these sensors and the good accuracy of the measurements obtained by them reported in the literature, these devices have shown difficulty in taking measurements when the volumetric moisture content of the soil is above 20%, greatly limiting the application of these, which are the simplest and cheapest sensors found in the literature. This paper therefore presents the design of a planar soil moisture sensor based on a microstrip antenna with a wide measuring range. The proposed sensor consists of a rectangular patch antenna designed to operate at 1.5 GHz. The device was designed with the FR-4 dielectric substrate (εr = 4.4 and tan(δ) = 0.02) and an interdigitated capacitor (IDC) integrated into the antenna patch. The simulated results showed that the proposed sensor-antenna is capable of taking measurements of the dielectric permittivity of solid materials without loss over a range of 1 to 26, with a maximum percentage resonance frequency shift (PRFS) of 57.14% and a minimum sensitivity of approximately 0.04 GHz at εr = 26, indicating that the proposed sensor may be capable of taking soil moisture measurements over a wide measurement range.

COMMITTEE MEMBERS:
Presidente - 2524053 - ANTONIO LUIZ PEREIRA DE SIQUEIRA CAMPOS
Interno - 1412682 - VICENTE ANGELO DE SOUSA JUNIOR
Externo à Instituição - ISAAC BARROS TAVARES DA SILVA