An Efficient Asymmetric Direct Current (DC) Source Configured Switched Capacitor Multi-level Inverter

This paper is dealing about Switched Capacitor Multi-Level Inverter (SCMLI) circuit which is controlled by triangular multicarrier Sinewave Pulse Width Modulation (SPWM) technique. The proposed SCMLI is powered from asymmetric DC source configuration to obtain multi-level output voltage by applying switching pulse to the main circuit from control circuit for switching operation. Fourteen switches and four capacitors are employing to do the proposed inversion operation in an effective way. Switching capacitors can perform boost operation to enhance voltage from the source level to the required level. Input DC from the asymmetric sources is converted to AC voltage for the application of consumers. This proposed conversion system is applicable for mainly in industrial and renewable energy-based energy conversion system because it can carry high output voltages. This proposed method gives about more efficiency. Also reduces switching losses in lower value, low conduction losses and capacitor ripple losses. The simulation model is analyzed in MATLAB/SIMULINK platform and the same validated in hardware results. The developed SCMLI structure is witness over other topologies for the power inversion process in the multi-level.

Design of Heterogenous Two-Element Array Antenna on an Electrically Thick Substrate for High Isolation and Low Pattern Correlation Using Modal Difference in Radiation Patterns

In this paper, we propose a novel design of a two-element array antenna on an electrical thick substrate with an extremely narrow array distance. The proposed array consists of a rectangular ring patch printed on a thick substrate and a monopole wire in the center of the substrate. Each element has a modal difference in the radiation pattern, causing high isolation and low correlation between the array elements. From the measurement results, the monopole and patch elements exhibit reflection coefficients of −10 dB and −10.7 dB with peak gains of 3.8 dBi and 6.1 dBi, respectively, at 1.6 GHz. The mutual coupling between the two elements is −20.7 dB. For modal analysis of the antenna pattern, spherical mode decomposition is performed on the radiation patterns of the two elements, and low envelope correlation coefficient levels below 16% are maintained. We also investigate the antijamming performance using a power inversion algorithm in a practical pattern nulling application; a null depth of −47.7 dB and a null width of 33.2° are obtained when the interference signal arrives at the elevation angle of 45°.

Impact of Element Pattern on the Performance of GNSS Power-Inversion Adaptive Arrays

Power-inversion (PI) adaptive arrays are widely used in Global Navigation Satellite System (GNSS) receivers for interference mitigation. The effects of element patterns on the performance of PI adaptive arrays are investigated in this paper. To this end, the performance of adaptive arrays is investigated by Monte Carlo simulations, using CST Microwave Studio (Dassault Systems, Vélizy-Villacoublay, France) to calculate the radiation patterns of circular microstrip elements which are used to compute the adaptive weight and the adaptive array gain. It is shown that the performance of PI adaptive arrays is mainly dependent on the gain pattern of the reference antenna element rather than the non-reference elements because the algorithm essentially pushes the elements into an unequal position. Furthermore, the results show that the impact of mutual coupling on the performance of the antenna array can be associated with the radiation patterns of the reference element, which is helpful in selecting the optimum reference element without increasing computational complexity, especially for small GNSS arrays.