A series of CoxAg1-x (0x100at.%) granular films were prepared using the ion-beam cosputtering technique at different substrate temperatures. Systematic investigations have been carried out on the giant magnetoresistance (GMR) effect and characterization of microstructures of these samples. The magnetoresistance ratio depends strongly on cobalt concentration, substrate temperature, and annealing treatment. The optimal value of GMR was observed in Co22Ag78 sample prepared at the temperature of 300 K. Microstructures of as-deposited and annealed samples were characterized by structural analyses. For Co22Ag78 sample, real-time in situ observation by TEM together with FMR spectra indicates that the size and shape of cobalt granules evolve primarily along the film plane during annealing. The results of FMR also provide that the cobalt granules remain single-domain particles after annealing at temperatures up to 700 K.

This paper presents novel structures of band-pass filters using two configurations of open loop ring resonators (OPLRR): a resonator with embedded quadruply-stepped impedance transmission lines (QSITL) in coupled lines, and a stepped impedance resonator (SIR). Both types of OPLRR have the capability of suppressing the second spurious response and shifting the third spurious response to a higher frequency as well. To demonstrate the performances of both proposed resonators, two sections of each structure with cascaded and crossed configurations at an operating frequency of 0.9 GHz are presented. Both methodologies are easy to design and implement. The methodology with a SIR has a better performance than the SITL. The measurement results of the proposed circuits are in full agreement with the simulated prediction results.