A fully differential R-MOSFET-C fourth-order Bessel active lowpass filter employing fully differential operational amplifier,passive resistors,and current-steering MOS transistors as a variable resistor is proposed.T...A fully differential R-MOSFET-C fourth-order Bessel active lowpass filter employing fully differential operational amplifier,passive resistors,and current-steering MOS transistors as a variable resistor is proposed.This proposed implementation relies on the tunability of current-steering MOS transistors operating in the triode region counteracting the concert deviation of resistor in the integrated circuit manufacturing technology in orde r that the group delay of Bessel active filter could be designed accurately.The amplifier is not only with voltage common-mode negative feedback,but also with current common-mode negative feedback,which will benefit for the stability of its D C operating point.0.75μs group delay fourth-order Bessel lowpass filter,whic h is synthesized according to passive doubly terminated RLC prototype lowpass filter,demonstrates better than -65dB THD using 100kHz,2.5V pp signal in Taiwan UMC 2P2M(2-poly,2-metal)5.0V,0.5μm CMOS technology.展开更多
Across the world, we are currently witnessing the deployments of 4 G LTE-Advanced and the 5 G research is reaching its peak point. The 5 G research mainly concentrates on addressing some of the existing OFDM based LTE...Across the world, we are currently witnessing the deployments of 4 G LTE-Advanced and the 5 G research is reaching its peak point. The 5 G research mainly concentrates on addressing some of the existing OFDM based LTE problems along with use of non-contiguous fragmented spectrum. Universal Filtered Multi Carrier(UFMC) has been considered as one of the candidate waveform for the 5 G communications because it provides robustness against the Inter Symbol Interference(ISI), and Inter Carrier Interference(ICI) and is suitable for low latency scenarios. In this paper, a novel approach is proposed to use Kaiser-Bessel filter based pulse shaping instead of standard Dolph-Chebyshev filter for UFMC based waveform to reduce the spectral leakage into nearby sub-bands. In this paper, UFMC system is simulated using MATLAB software, a comparative study for Dolph-Chebyshev and Kaiser-Bessel filters are performed and the results are also presented in terms of power spectrum density(PSD) analysis, Complementary Cumulative Distribution Function(CCDF) analysis, and Adjacent Channel Power Ratio(ACPR) analysis. The simulated results show a better power spectral density and lower sidebands for UFMC(Kaiser Based window), when compared with UFMC(Dolph-Chebyshev) and conventional OFDM.展开更多
文摘A fully differential R-MOSFET-C fourth-order Bessel active lowpass filter employing fully differential operational amplifier,passive resistors,and current-steering MOS transistors as a variable resistor is proposed.This proposed implementation relies on the tunability of current-steering MOS transistors operating in the triode region counteracting the concert deviation of resistor in the integrated circuit manufacturing technology in orde r that the group delay of Bessel active filter could be designed accurately.The amplifier is not only with voltage common-mode negative feedback,but also with current common-mode negative feedback,which will benefit for the stability of its D C operating point.0.75μs group delay fourth-order Bessel lowpass filter,whic h is synthesized according to passive doubly terminated RLC prototype lowpass filter,demonstrates better than -65dB THD using 100kHz,2.5V pp signal in Taiwan UMC 2P2M(2-poly,2-metal)5.0V,0.5μm CMOS technology.
文摘Across the world, we are currently witnessing the deployments of 4 G LTE-Advanced and the 5 G research is reaching its peak point. The 5 G research mainly concentrates on addressing some of the existing OFDM based LTE problems along with use of non-contiguous fragmented spectrum. Universal Filtered Multi Carrier(UFMC) has been considered as one of the candidate waveform for the 5 G communications because it provides robustness against the Inter Symbol Interference(ISI), and Inter Carrier Interference(ICI) and is suitable for low latency scenarios. In this paper, a novel approach is proposed to use Kaiser-Bessel filter based pulse shaping instead of standard Dolph-Chebyshev filter for UFMC based waveform to reduce the spectral leakage into nearby sub-bands. In this paper, UFMC system is simulated using MATLAB software, a comparative study for Dolph-Chebyshev and Kaiser-Bessel filters are performed and the results are also presented in terms of power spectrum density(PSD) analysis, Complementary Cumulative Distribution Function(CCDF) analysis, and Adjacent Channel Power Ratio(ACPR) analysis. The simulated results show a better power spectral density and lower sidebands for UFMC(Kaiser Based window), when compared with UFMC(Dolph-Chebyshev) and conventional OFDM.
