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
A monolithic single pole single throw （SPST） switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an...A monolithic single pole single throw （SPST） switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an on-state insertion loss of less than 1.6dB and a return loss of greater than 10dB while maintaining an off-state isolation of greater than 23dB from 5.5 to 7. 5GHz. The measured 1dB power gain compression point is about 20dBm.展开更多
By combining multiscale stationary wavelet analysis with fuzzy c-means, a robust edge detection algorithm is presented. Based on the translation invafiance built in multiscale stationary wavelet transform, components ...By combining multiscale stationary wavelet analysis with fuzzy c-means, a robust edge detection algorithm is presented. Based on the translation invafiance built in multiscale stationary wavelet transform, components in different transformed sub-images corresponding to a pixel are employed to form a feature vector of the pixel. All the feature vectors are classified with unsupervised fuzzy c-means to segment the image, and then the edge pixels are checked out by the Canny detector. A series of images contaminated with different intensive Gaussian noises are used to test the novel algorithm. Experiments show that fairly precise edges can be checked out robustly from those images with fairly intensive noise by the proposed algorithm.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A monolithic single pole single throw （SPST） switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an on-state insertion loss of less than 1.6dB and a return loss of greater than 10dB while maintaining an off-state isolation of greater than 23dB from 5.5 to 7. 5GHz. The measured 1dB power gain compression point is about 20dBm.
文摘By combining multiscale stationary wavelet analysis with fuzzy c-means, a robust edge detection algorithm is presented. Based on the translation invafiance built in multiscale stationary wavelet transform, components in different transformed sub-images corresponding to a pixel are employed to form a feature vector of the pixel. All the feature vectors are classified with unsupervised fuzzy c-means to segment the image, and then the edge pixels are checked out by the Canny detector. A series of images contaminated with different intensive Gaussian noises are used to test the novel algorithm. Experiments show that fairly precise edges can be checked out robustly from those images with fairly intensive noise by the proposed algorithm.
