This paper presents a 155Mbps limiting amplifier for STM-1 systems of SDH optical communication. It is implemented in CSMC 0.5μm CMOS technology. Under a supply voltage of 3.3V, it has a power consumption of 198mW. T...This paper presents a 155Mbps limiting amplifier for STM-1 systems of SDH optical communication. It is implemented in CSMC 0.5μm CMOS technology. Under a supply voltage of 3.3V, it has a power consumption of 198mW. The core of the circuit is composed of 6 cascaded amplifiers that are in a conventional structure of differential pairs,an output buffer, and a DC offset cancellation feedback loop. The small signal gain can be adjusted from 74 to 44dB by an off-chip resistor. The chip was packaged before being tested. The experimental results indicate that the circuit has an input dynamic range of 54dB and provides a single-ended output swing of 950mV. Its output eye diagram remains satisfactory when the pseudo-random bit sequence （PRBS） input speed reaches 400Mbps.展开更多
The normal forms of generalized Neimark-Sacker bifurcation are extensively studied using normal form theory of dynamic system. It is well known that if the normal forms of the generalized Neimark-Sacker bifurcation ar...The normal forms of generalized Neimark-Sacker bifurcation are extensively studied using normal form theory of dynamic system. It is well known that if the normal forms of the generalized Neimark-Sacker bifurcation are expressed in polar coordinates, then all odd order terms must, in general, remain in the normal forms. In this paper, five theorems are presented to show that the conventional Neimark-Sacker bifurcation can be further simplified. The simplest normal forms of generalized Neimark-Sacker bifurcation are calculated. Based on the conventional normal form, using appropriate nonlinear transformations, it is found that the generalized Neimark-Sacker bifurcation has at most two nonlinear terms remaining in the amplitude equations of the simplest normal forms up to any order. There are two kinds of simplest normal forms. Their algebraic expression formulas of the simplest normal forms in terms of the coefficients of the generalized Neimark-Sacker bifurcation systems are given.展开更多
Driven by the rapid development of agricultural science and technology, many techniques have been developed rapidly, especially the development of broadcasting technology which earth-shaking changes have taken place. ...Driven by the rapid development of agricultural science and technology, many techniques have been developed rapidly, especially the development of broadcasting technology which earth-shaking changes have taken place. The advent of digital broadcasting technology makes the broadcast technology enter a new stage. With its low energy consumption and large coverage area, digital broadcasting technology was widely welcomed by the broadcast television industry. This paper analyzes digital audio broadcasting, multimedia digital broadcasting and digital AM broadcasting, and further concretely elaborates the application prospects of digital broadcasting technology.展开更多
Amplitude quantization is one of the main sources of spurious noise frequencies in Direct Digital Frequency Synthesizers (DDFSs), which affect their application to many wireless telecommu- nication systems. In this pa...Amplitude quantization is one of the main sources of spurious noise frequencies in Direct Digital Frequency Synthesizers (DDFSs), which affect their application to many wireless telecommu- nication systems. In this paper, two different kinds of spurious signals due to amplitude quantization in DDFSs are exactly formulated in the time domain and detailedly compared in the frequency do- main, and the effects of the DDFS parameter variations on the spurious performance are thoroughly studied. Then the spectral properties and power levels of the amplitude-quantization spurs in the absence of phase-accumulator truncation are emphatically analyzed by waveform estimation and computer simulation, and several important conclusions are derived which can provide theoretical support for parameter choice and spurious performance evaluation in the application of DDFSs.展开更多
文摘This paper presents a 155Mbps limiting amplifier for STM-1 systems of SDH optical communication. It is implemented in CSMC 0.5μm CMOS technology. Under a supply voltage of 3.3V, it has a power consumption of 198mW. The core of the circuit is composed of 6 cascaded amplifiers that are in a conventional structure of differential pairs,an output buffer, and a DC offset cancellation feedback loop. The small signal gain can be adjusted from 74 to 44dB by an off-chip resistor. The chip was packaged before being tested. The experimental results indicate that the circuit has an input dynamic range of 54dB and provides a single-ended output swing of 950mV. Its output eye diagram remains satisfactory when the pseudo-random bit sequence （PRBS） input speed reaches 400Mbps.
基金Supported by National Natural Science Foundation of China (No10872141)Doctoral Foundation of Ministry of Education of China (No20060056005)Natural Science Foundation of Tianjin University of Science and Technology (No20070210)
文摘The normal forms of generalized Neimark-Sacker bifurcation are extensively studied using normal form theory of dynamic system. It is well known that if the normal forms of the generalized Neimark-Sacker bifurcation are expressed in polar coordinates, then all odd order terms must, in general, remain in the normal forms. In this paper, five theorems are presented to show that the conventional Neimark-Sacker bifurcation can be further simplified. The simplest normal forms of generalized Neimark-Sacker bifurcation are calculated. Based on the conventional normal form, using appropriate nonlinear transformations, it is found that the generalized Neimark-Sacker bifurcation has at most two nonlinear terms remaining in the amplitude equations of the simplest normal forms up to any order. There are two kinds of simplest normal forms. Their algebraic expression formulas of the simplest normal forms in terms of the coefficients of the generalized Neimark-Sacker bifurcation systems are given.
文摘Driven by the rapid development of agricultural science and technology, many techniques have been developed rapidly, especially the development of broadcasting technology which earth-shaking changes have taken place. The advent of digital broadcasting technology makes the broadcast technology enter a new stage. With its low energy consumption and large coverage area, digital broadcasting technology was widely welcomed by the broadcast television industry. This paper analyzes digital audio broadcasting, multimedia digital broadcasting and digital AM broadcasting, and further concretely elaborates the application prospects of digital broadcasting technology.
基金Supported by National High-Technology Research and Development Plan of China (Grant No.2006AA01Z452)
文摘Amplitude quantization is one of the main sources of spurious noise frequencies in Direct Digital Frequency Synthesizers (DDFSs), which affect their application to many wireless telecommu- nication systems. In this paper, two different kinds of spurious signals due to amplitude quantization in DDFSs are exactly formulated in the time domain and detailedly compared in the frequency do- main, and the effects of the DDFS parameter variations on the spurious performance are thoroughly studied. Then the spectral properties and power levels of the amplitude-quantization spurs in the absence of phase-accumulator truncation are emphatically analyzed by waveform estimation and computer simulation, and several important conclusions are derived which can provide theoretical support for parameter choice and spurious performance evaluation in the application of DDFSs.
