Investigating the Effects of Uniaxial Pressure on the Preparation of
MgTiO3-CaTiO3 Ceramic Capacitors for MRI Systems
Abstract
Today’s healthcare system relies on MRI (medical resonance imaging) for
early diagnosis and treatment planning. For open MRI systems to achieve
resolutions of about a hundred microns, a high voltage is required, as
well as a specialized power supply. NP0 (Negative-Positive-Zero) ceramic
is selected for the fabrication of adjustable capacitors. Specifically,
it stands for which is a classification based on the temperature
coefficient of capacitance (TCC) of the ceramic material used in the
capacitor. NP0 capacitors have a TCC of 0 ±30 ppm/°C, which means that
their capacitance value does not change significantly with temperature
and frequency. They are known for their stability and low losses, making
them ideal for applications that require high accuracy and reliability,
such as timing circuits for RF applications. In this paper, MgTiO-CaTiO
ceramic is used to make an adjustable capacitor with desired properties
for MRI systems. To enhance the dielectric properties of MgTiO3
ceramics,CaTiO3 was added in varying concentrations. After pressing and
sintering, the resulting samples were tested using a vector network
analyzer in the frequency range of 10 MHz to 130 MHz.The adjustable
capacitor fabricated using high co-fired NP0 ceramic may have been used
for MRI applications such as tuning circuits and matching networks,
where precise capacitance values and low loss are critical[1]. MRI
systems with resonance frequencies of 128 MHz require trimmers with
ceramic cores.