The instantaneous frequency （IF） estimation of the linear frequency modulated （LFM） signals with time-varying amplitude using the peak of the Wigner-Ville distribution （WVD） is studied. Theoretical analysis show...The instantaneous frequency （IF） estimation of the linear frequency modulated （LFM） signals with time-varying amplitude using the peak of the Wigner-Ville distribution （WVD） is studied. Theoretical analysis shows that the estimation on LFM signals with time-varying amplitude is unbiased, only if WVD of time-varying amplitude reaches its maximum at frequency zero no matter in which time. The statistical performance in the case of additive white Guassian noise is evaluated and an analytical expression for the variance is provided. The simulations using LFM signals with Gaussian envelope testify that IF can be estimated accurately using the peak of WVD for four models of amplitude variation. Furthermore the statistical result of estimation on the signals with amplitude descending before rising is better than that of the signals with constant amplitude when the amplitude variation rate is moderate.展开更多
Gate-grounded NMOS （GGNMOS） devices with different device dimensions and layout floorplans have been designed and fabricated in 0.13-μm silicide CMOS technology. The snapback characteristics of these GGN-MOS device...Gate-grounded NMOS （GGNMOS） devices with different device dimensions and layout floorplans have been designed and fabricated in 0.13-μm silicide CMOS technology. The snapback characteristics of these GGN-MOS devices are measured using the transmission line pulsing （TLP） measurement technique. The relationships between snapback parameters and layout parameters are shown and analyzed. A TCAD device simulator is used to explain these relationships. From these results, the circuit designer can predict the behavior of the GGNMOS devices under high ESD current stress, and design area-efficient ESD protection circuits to sustain the required ESD level. Optimized layout rules for ESD protection in 0.13-μm silicide CMOS technology are also presented.展开更多
文摘The instantaneous frequency （IF） estimation of the linear frequency modulated （LFM） signals with time-varying amplitude using the peak of the Wigner-Ville distribution （WVD） is studied. Theoretical analysis shows that the estimation on LFM signals with time-varying amplitude is unbiased, only if WVD of time-varying amplitude reaches its maximum at frequency zero no matter in which time. The statistical performance in the case of additive white Guassian noise is evaluated and an analytical expression for the variance is provided. The simulations using LFM signals with Gaussian envelope testify that IF can be estimated accurately using the peak of WVD for four models of amplitude variation. Furthermore the statistical result of estimation on the signals with amplitude descending before rising is better than that of the signals with constant amplitude when the amplitude variation rate is moderate.
基金supported by the National Natural Science Foundation of China(Nos.60773081,60777018)the AM Foundation by Science and Technology Commission of Shanghai Municipality(No.087009741000)the SDC Project by Science and Technology Commission of Shanghai Municipality(Nos.08706201800,077062008,08706201000)
文摘Gate-grounded NMOS （GGNMOS） devices with different device dimensions and layout floorplans have been designed and fabricated in 0.13-μm silicide CMOS technology. The snapback characteristics of these GGN-MOS devices are measured using the transmission line pulsing （TLP） measurement technique. The relationships between snapback parameters and layout parameters are shown and analyzed. A TCAD device simulator is used to explain these relationships. From these results, the circuit designer can predict the behavior of the GGNMOS devices under high ESD current stress, and design area-efficient ESD protection circuits to sustain the required ESD level. Optimized layout rules for ESD protection in 0.13-μm silicide CMOS technology are also presented.
