Smart Antenna using Switched Multibeam Array Ms
This paper describes the design and realization of a 44 Butler Matrix as a beam forming network along with 4 linear antenna arrays to obtain four steerable beams, operating at 2.4 GHz. The simulation results are obtained using HFSS software. Further the concept of multibeam switching is discussed with an idea of suspended feed in between two matrices.
4×4 Butler Matrix Beam Forming Network using Novel Reduced Size Branchline Coupler
This paper presents a reduced size quadrature branch-line coupler that has achieved size reduction by approximately up to 80% without having to compromise performance. This design is realized on a low cost substrate (FR4, 0.50mm, ¿r = 4.4), yields an excellent return loss (¿49.0dB) and coupling loss (¿3.30 ~ ¿3.50dB) characteristics at 1.8GHz. The practical application of this novel reduced size branch-line coupler has been implemented and demonstrated in a 4×4 Butler Matrix beam-forming network operating at 1.7-2.0GHz.
Mathematical Modeling of Scour and Deposition
Electronic computers are opening up the field of sedimentation engineering by permitting the analysis of problems which heretofore have required too much time and effort. Movable stream bed profiles are being calculated in addition to water surface profiles. The initial gradation of sediment material in the stream bed may be prescribed to facilitate the calculation of an armor layer. This gradation is continually changed by the computer program in response to sediment particles being deposited on the stream bed and material on the stream bed being removed to satisfy transport capacity. Hydraulic sorting of sediment by grain size is accomodated. The stream bed does not have to be represented by a single grain size. Retardance of motion because of armor layer is calculated.