A complete behavioral model of radiation-pattern characteristics of phased array using a novel digital phase shifter
A complete and behavioral model for radiation-pattern characteristic of phased array has been presented. The model has many input parameters and it has a lot of features, such as parameter simulations with results analysis, unconventional two-dimensional color graph representation capability in order to show more clearly the results. It is an optimum instrument to investigate the performance of a beam-former in relation with an analogue phase shifter, ideal digital phase shifter, simulated real phase shifter and measured real phase shifter. Measured values of three different prototype of the proposed phase shifter architecture have been used in order to study the performances of the same architecture.
The effect of phase-shifter errors on the performance of an antenna-array beamformer
The paper considers the random phase errors in the phase shifters which are used in an antenna array to steer the beam in the look direction, and analyzes the effect of these errors on the performance of the optimal processor which maximizes the output SNR by deriving the expressions for the output signal power, residual interference power, output SNR, and the array gain as a function of the variance of these errors. The paper also considers the phase quantization error which arises in the digital phase shifters and shows how the performance of the optimal processor depends on the number of bits of the digital phase shifters.
Mineral element analyses of various tropical forages in Guatemala and their relationship to soil concentrations
Determination de la composition minerale de differents fourrages dans 3 regions d'elevage du Guatemala et etude des relations entre la chimie des sols et la composition minerale des fourrages