VASANI, ANAND JITENDRA Design of Frequency Agile Circuits Using Barium Strontium Titanate Varactor. (Under the direction of Prof. Kevin G. Gard). Multi-standard and multi-band radio are the next milestone in the ever developing radio industry. Frequency agile circuits are an enabling technology which allows us to achieve this goal. It is a low cost and efficient technology that provides the nec...

Barium titanate is a member of a large family of compounds with the general formula ABO3 called perovskites, as the crystal size of barium titanate increases and at critical crystalline size crystal structure of barium titanate transformed from cubic to tetragonal. Transformation of crystal structure is also take place at Curi temperature. Cubic structure show paramagenatic behavior while tetra...

Particles are important additives for altering and enhancing the properties of polymers. When the particle size approaching the fundamental length scale of the material, new mechanical, optical, and electrical properties arise, which are not present in the conventional macroscopic counterpart. For example, the dielectric constant of a polymer fluid can be increased by addition of ceramic nanopa...

A theoretical treatment, based on the Devonshire theory of ferroelectrics, is presented to describe the storage of electrostatic energy in ferroelectric and paraelectric materials at very high field strengths. In all cases, optimal energy density is achieved by using compositions with Curie temperatures well below the operating temperature. The theory is applied to barium–strontium titanate cer...

In most electronic materials the change in dielectric constant with applied electric field is an effect too small to be useful or even easily measurable. But for a special class of highpermittivity materials the effect can be quite pronounced. This chapter explores some challenges and opportunities for exploiting tunable dielectrics to make reconfigurable, adaptive, frequency-agile RF devices. ...