A 1 GHz Sample Rate, 100-Channel, 2-Bit, Single-Chip CMOS Digital Correlator Spectrometer

建议的相关器芯片用于射电天文学的两个主要应用领域：孔径合成阵列中的互相关谱以及厘米和毫米波长的自相关谱。第一阶段的目标是设计、模拟和布局具有以下特性的cmos数字相关器芯片：a)1 GHz采样率，b)10个通道，c)2位(4级)量化，d)32位计数器/累加器。实验证明，采用脉动结构、新颖的流水线差分逻辑电路和1.0um工艺相结合，可以实现1 GHz的采样率。第二阶段的目标是将每个芯片的通道数量增加到100个，同时保持1 GHz时钟频率和4级量化方案。还将为若干特征编列经费，例如太阳爆发观测的1位相关、脉冲星观测的相关系数的消隐和相位切换模式。相关芯片的商业市场在1992年估计为200万至500万美元，并将以每年15%至20%的速度增长。目前，大多数数字相关器芯片都是由每个射电天文实验室自行设计的，供各自内部使用。建议的相关器芯片的性价比将比现有的相关器高出10倍。

The proposed correlator chip is intended for the two main application areas in radio astronomy: cross-correlation spectroscopy in aperture synthesis arrays and autocorrelation spectroscopy at cm and mm wavelengths. The objectives of Phase I are to design, simulate, and layout a CMOS digital correlator chip with the following characteristics: a) 1 GHz sample rate, b) 10 channels, c) 2-bit (four-level) quantization, and d) 32-bit counter/accumulator. It has already been demonstrated experimentally that the 1 GHz sampling rate can be achieved with a combination of systolic architecture, novel pipeline differential logic circuits, and a 1.0 um CMOS fabrication process. The objectives of Phase II are to increase the number of channels per chip to 100 while maintaining the 1 GHz clock frequency and the 4-level quantization scheme. Provision will also be made for a number of features such as 1-bit correlation for solar burst observation, blanking of correlation coefficients for pulsar observations, and phase switch mode. The commercial market for correlator chips is estimated at two to five million dollars in 1992 and it will grow 15% to 20% annually. Presently, most digital correlator chips are designed by each radio astronomy laboratory for their own internal use. The performance- to-cost ratio of the proposed correlator chip will be up to 10 times higher than that of existing correlators.