Multilevel inverters have end up more popular over time in electric excessive power utility with the promise of less disturbances and the possibility to characteristic at lower switching frequencies than everyday two-stage inverters. This paper provides information about, reduced device count multilevel inverter topologies & its modulation schemes. Here also compared the hybrid multilevel inverters (Reversing voltage Multilevel inverter) with and without the usage of SPWM method & shown that, the harmonic distortion of the output Voltage waveform decreases in the RV MLI's. These multilevel inverters will also be compared with conventional multi level topologies to investigate the advantages of using hybrid topology. Basic switching, Modulation strategies & component comparison will also be presented in this work.

No abstract

No abstract

In this paper, a novel 128-Point FFT/IFFT processor for OFDM-based UWB system has been proposed. In proposed MRMDF (Mixed Radix Multipath Delayed Feedback) architecture, high throughput rate can be achieved by using four data paths. Furthermore, the hardware costs of memory and complex multiplier can be saved by adopting delay feedback and data scheduling approaches. In addition, the number of complex multiplications is reduced effectively by using a higher radix algorithm. The measurement results show that the throughput rate of this test chip is up to 1Gsample/s while it dissipates 175mW. When the throughput rate of our processor meets UWB standard, it only consumes 77.6 mW and multiplexers. The features of the proposed MRMDF architecture are the following:• Higher throughput rate can be provided by using four parallel data paths;• The minimum memory is required by using the delay feedback approach to reorder the input data and the intermediate results of each module.• The 128-point mixed-radix FFT/IFFT algorithm is implemented to power consumption.• The number of complex multiplier is minimized by using the scheduling scheme and the specified constant multipliers.