In contrast to low-frequency EMI, high-frequency electromagnetic induction (HFEMI) sensors operate in the frequency range between 300 kHz and 30 MHz. They operate in the low-frequency range below 300 kHz, where they are sensitive to electrical conductivity and magnetic susceptibility. Most EMI soil sensors consist of transmitter and receiver coils at the intercoil separation corresponding to the soil exploration depth. The results agree well with the results of a finite element method analysis.Įlectromagnetic induction (EMI) sensing is used as a noncontact method for the measurement of soil electromagnetic parameters (electrical conductivity, dielectric permittivity and magnetic susceptibility) related to physical and chemical properties such as soil salinity, water content and density.
In the case study, we experimentally analyze the HFEMI sensor above a saline solution for two shield configurations. We theoretically and experimentally evaluate a typical HFEMI sensor and its shielding in the frequency range of up to 20 MHz and propose a method for evaluating the effectiveness of a shield configuration. In this paper, we introduce the discussion on the relationship between the sensor geometry, shielding and the coupling mechanisms for HFEMI soil sensing. The remnant capacitive coupling after the implementation of shielding can lead to significant difficulties in the sensor signal interpretation, because both coupling mechanisms are highly dependent on the geometry of the HFEMI sensor and applied shield. Because of the high-frequency operation, the capacitive coupling between the sensor transmitter and receiver coils is comparable to inductive coupling, creating the need for electrostatic shielding. Finally the parameters are re adjusted to obtain our desired Larmor frequency 298.2 MHz for a correct operation in 7T.High-frequency electromagnetic induction (HFEMI) sensors, operating in the frequency range from 300 kHz to 30 MHz, have been proposed for the measurement of soil electrical conductivity and dielectric permittivity that are related to the physical and chemical properties of soil.
#Cst studio suite coil function simulator#
Firstly we design a birdcage coil then the results are obtained with simulator CST Wave Studio, creating a 3D model and generating a simulation. It opens the door to design and construct a Birdcage coil for a 7T to obtain human brain images. Design of a Birdcage coil for a 7T to obtain the images from s mall animals (i.e. The birdcage coil achieves circular polarization and generates a high homogeneous radio frequency magnetic field under many conditions. This research work presented recent developments based on high field 7T design using CST studio. Moreover, a better SNR increases the spatial resolution or reduces the imaging time. Higher strength field generates a better SNR and increased chemical shift effect, improving spectral fat suppression and spectroscopy. The principal objective is the design of a birdcage Radio Frequency (RF) coil to use in a 7 Tesla (7T) scanner. This work describes the study of coils for Magnetic Resonance Imaging (MRI) applications.
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