The wide-band digital receiving systems require digital downconversion(DDC) with high data rate and short tuning time in order to intercept the narrow-band signals within broad tuning bandwidth. But these requirements...The wide-band digital receiving systems require digital downconversion(DDC) with high data rate and short tuning time in order to intercept the narrow-band signals within broad tuning bandwidth. But these requirements can not be met by the commercial DDC. In this paper an efficient implementation architecture is presented. It combines the flexibility of DFT tuning with the efficiency of the polyphase filter bank decomposition. By first decimating the data prior to filtering and mixing, this architecture gives a better solution to the mismatch between the lower hardware speed and high data rate. The computer simulations show the feasibility of this processing architecture.展开更多
The purpose of this paper is to design a portable two linearly polarized beams absorption biometric system (PTLPBABS) that measures the amount of absorption of the visible collimated beam passing by the sample to know...The purpose of this paper is to design a portable two linearly polarized beams absorption biometric system (PTLPBABS) that measures the amount of absorption of the visible collimated beam passing by the sample to know the absorbance of the sample. The measured object in the system is the gold colloid that the sample produces after a biochemical reaction. After measuring the absorbance of the gold colloid we can obtain the concentrations of the waiting-measured sample and further obtain the concentration of chemical solution contained in the sample. The two linearly polarized beams device can be used to enhance rejection of ambient light and causes PTLPBABS to have excellent data stability measured. The process of the double optical path method increases the opportunities that the visible collimated beam is absorbed, which raise the detection sensitivity of the system to a sensitivity of 0.1%.展开更多
文摘The wide-band digital receiving systems require digital downconversion(DDC) with high data rate and short tuning time in order to intercept the narrow-band signals within broad tuning bandwidth. But these requirements can not be met by the commercial DDC. In this paper an efficient implementation architecture is presented. It combines the flexibility of DFT tuning with the efficiency of the polyphase filter bank decomposition. By first decimating the data prior to filtering and mixing, this architecture gives a better solution to the mismatch between the lower hardware speed and high data rate. The computer simulations show the feasibility of this processing architecture.
文摘The purpose of this paper is to design a portable two linearly polarized beams absorption biometric system (PTLPBABS) that measures the amount of absorption of the visible collimated beam passing by the sample to know the absorbance of the sample. The measured object in the system is the gold colloid that the sample produces after a biochemical reaction. After measuring the absorbance of the gold colloid we can obtain the concentrations of the waiting-measured sample and further obtain the concentration of chemical solution contained in the sample. The two linearly polarized beams device can be used to enhance rejection of ambient light and causes PTLPBABS to have excellent data stability measured. The process of the double optical path method increases the opportunities that the visible collimated beam is absorbed, which raise the detection sensitivity of the system to a sensitivity of 0.1%.
