Abstract: One of the important components in many RF ICs applications is the transformer. It is very important that transformer has optimal design, that means, optimal geometry with the best possible characteristics. Because of the wide transformer applications in radio-frequency silicon-based circuits, modeling for transformers has become more and more essential. The modeling of planar transformer for very high frequencies is the subject of this paper. Square, polygonal and circular shapes of the planar windings are the important difference regarding transformer topologies. In this work, comparison was restricted to a square and an octagonal shape of the windings. In this study, we opted for calculation method developed by Wheeler to evaluate the inductance of different planar geometrical shapes of transformer windings. Besides, we determined the geometrical parameters of the transformer and from its π-electrical model; we highlighted all parasitic effects generated by stacking of different material layers. By using the S-parameters, we calculated the technological parameters. The important characteristics of a transformer are its inductances values and its parasitic capacitances and resistances, which determine its Q factor and self-resonant frequency. Furthermore, we carried out the electromagnetic simulation using COMSOL Multiphysics 4.3 software to show current density and electromagnetic field in the windings of the transformer for high frequencies.Abstract: One of the important components in many RF ICs applications is the transformer. It is very important that transformer has optimal design, that means, optimal geometry with the best possible characteristics. Because of the wide transformer applications in radio-frequency silicon-based circuits, modeling for transformers has become more and more esse...Show More
Abstract: In this study, two fabrics were collected from jute research institute, Bangladesh consisting of 80% Jute & 20% cotton yarn; 50% Jute and 50% Cotton yarn by weight, to make comparison between the samples. The tearing strength (TS), drape coefficient, Pilling resistance, Color fastness to wash & rubbing, water take up% and Color strength were investigated. From analyzed data, it was found that tearing strength in warp and weft way direction is higher for 80% jute and 20% cotton blended fabric. From results it was seen that in warp direction, tearing strength for 80% and 20% cotton blended fabric is 4% higher than 50% jute and 50% cotton blended woven fabric but in weft direction 356% higher for 80% jute and 20% cotton blended woven fabric. Color fastness to rubbing is comparatively better for 50% jute and 50% cotton blended sample. Wash fastness property is almost same for both blended samples. But jute prominence sample carried poor wash fastness property on blended cotton and polyamide in compare equally blended sample. Moderate pills are formed on 50% cotton and 50% jute blended fabric and slight surface fuzzing and/ or partially formed pills on 80% jute and 20% cotton blended sample. Drape resistance property is better for jute prominence blended fabric. Color strength is almost same for both samples.Abstract: In this study, two fabrics were collected from jute research institute, Bangladesh consisting of 80% Jute & 20% cotton yarn; 50% Jute and 50% Cotton yarn by weight, to make comparison between the samples. The tearing strength (TS), drape coefficient, Pilling resistance, Color fastness to wash & rubbing, water take up% and Color strength were invest...Show More
