Figure 1

Conceptual illustration of the timeline and working of the sensor tags (a) Sensor tags are distributed in the fields using a sower machine or an automated dispenser at the onset of the crop season. (b) A drone carrying an RF reader reads each of the sensor tags in the network during the crop season. (c) After the crop season, the sensor tags undergo a gradual process of biodegradation through the following seasons. (d) System configuration with the reader antenna interrogating the sensor tags buried in the soil. Maximum backscattering is obtained at the resonant frequency, \({f}_{r}\), and \({f}_{r}\) varies based on the dryness or wetness of the soil. (e) Cross-sectional illustration of the capacitance distribution in a meander line structure encapsulated with passivation layers that forms DIRTS. (f) Equivalent circuit diagram of DIRTS (g) 3D far-field pattern of DIRTS demonstrating the maximum direction of radiation along the z-axis (h) Cross-sectional schematic at \(\Phi\)=0 demonstrating the orientation dependence and the main lobe direction of DIRTS.