Temperature compensated stripline structure

Abstract

A stripline structure has a stabilized resonant frequency against temperature variations. It includes a lower and an upper substrate of ceramic materials, each substrate having opposing inner and outer surfaces. Each of the outer surfaces are covered with a layer of conductive material constituting ground planes. Resonator strips of conductive material are situated on each of the inner surfaces, and each have one end connected to the ground, while the opposite end is an open circuit. The upper and lower substrates are bonded together along the length of their respective resonator strips, thereby producing the stripline structure. The length of the resonator determines the resonant frequency of the stripline structure. The two substrates are made of materials having opposite dielectric temperature coefficient. The physical parameters of the stripline structure, such as, thicknesses of the substrates, the widths of the resonator strips, or both can be adjusted in order to produce a net zero, positive or negative frequency temperature coefficient. Furthermore the substrates can be made of dielectric or ferrite materials.