초록 ▼

A method and apparatus for improving microprocessor data acquisition. Noise in analog signals is removed by a low pass filter with a variable cutoff frequency controlled to cut off all frequencies above a frequency range of interest. The filtered signal is sampled by an analog-to-digital converter a

A method and apparatus for improving microprocessor data acquisition. Noise in analog signals is removed by a low pass filter with a variable cutoff frequency controlled to cut off all frequencies above a frequency range of interest. The filtered signal is sampled by an analog-to-digital converter at a sampling rate which is variable and controlled to sample at a rate that is at least two times the low pass filter cutoff frequency thereby reducing the rate at which data is passed to a microprocessor and reducing the need for speed in the microprocessor's processing.

대표청구항 ▼

A method and apparatus for improving microprocessor data acquisition. Noise in analog signals is removed by a low pass filter with a variable cutoff frequency controlled to cut off all frequencies above a frequency range of interest. The filtered signal is sampled by an analog-to-digital converter a

A method and apparatus for improving microprocessor data acquisition. Noise in analog signals is removed by a low pass filter with a variable cutoff frequency controlled to cut off all frequencies above a frequency range of interest. The filtered signal is sampled by an analog-to-digital converter at a sampling rate which is variable and controlled to sample at a rate that is at least two times the low pass filter cutoff frequency thereby reducing the rate at which data is passed to a microprocessor and reducing the need for speed in the microprocessor's processing. is permeability of the object being analyzed; and said second-half stage processing means calculates the new state of the electromagnetic wave at the second time point and at every grid point (i, j) on the x-y plane, according to the following equations where Exn+1i+1/2,jdenotes an z-direction electric field component at the second time point and at space point (i+1/2, j), Eyn+1i,j+1/2 denotes a y-direction electric field component at the second time point and at space point (i, j+1/2), and Hzn+1i+1/2,j+1/2denotes a z-direction magnetic field component at the second time point and at space point (i+1/2, j+1/2). 6. The electromagnetic wave analyzer according to claim 1, wherein said analyzing means analyzes propagation of a two-dimensional TM wave. 7. The electromagnetic wave analyzer according to claim 6, wherein an x-y plane is defined as a plane on which magnetic field components of the electromagnetic wave lie; the initial conditions and parameters established by said analysis command input means include spatial discretization intervals Δxand Δyto discretize the x-y plane in x and y directions, respectively; and said analyzing means analyzes the electromagnetic wave around a grid point (i, j) on the x-y plane by calculating an x-direction magnetic field component at space point (i, j+1/2), a y-direction magnetic field component at space point (i+1/2, j), and a z-direction electric field component at space point (i, j) which is perpendicular to the x-y plane. 8. The electromagnetic wave analyzer according to claim 7, wherein said analyzing means comprises: first-half stage processing means for calculating a state of the electromagnetic wave at an intermediate time point that is Δt/2 after the first time point, based on the state of the electromagnetic wave at the first time point, by using an explicit method to calculate the x-direction magnetic field component, as well as an implicit method to calculate the y-direction magnetic field component and the z-direction electric field component; and second-half stage processing means for calculating the new state of the electromagnetic wave at the second time point, based on the state of the electromagnetic wave at the intermediate time point supplied from said first-half stage processing means, by using an explicit method to calculate the y-direction magnetic field component, as well as an implicit method to calculate the x-direction magnetic field component and the z-direction electric field component. 9. The