Reduction of the temperature coefficient in high permittivity dielectric resonators for pre-clinical MRI purposes

Motivation: High permittivity dielectric resonators for high resolution MRI are fabricated ferroelectric materials and have a large temperature coefficient, which produces a significant frequency variation in a small temperature range. Goal(s): Reduce the temperature coefficient in dielectric resonators through a composite design. Approach: Depending on the Curie temperature of BST, single layered dielectric resonators have positive or negative temperature dependance of resonant frequency. Bi-layered resonators combine positive and negative coefficients to create a temperature stable resonant frequency. Results: Bi-layered resonators show on average a 75% reduction in frequency variation compared to single layers. Impact: Bi-layered resonators are a first step in overcoming high temperature coefficients present in high permittivity dielectric resonators. With further improvements, this method can be used to significantly increase SNR in preclinical studies.