Impulse-equivalent time-domain optical memory

1996 ◽  
Author(s):  
Xiao A. Shen ◽  
Ravinder Kachru
Keyword(s):  
Time Domain ◽  
Optical Memory ◽  
Equivalent Time

Impulse-equivalent time-domain optical memory

1996 ◽  
Vol 21 (11) ◽  
pp. 833 ◽  
Author(s):  
X. A. Shen ◽  
R. Hartman ◽  
R. Kachru
Keyword(s):  
Time Domain ◽  
Optical Memory ◽  
Equivalent Time

scholarly journals A time domain spherical near-field measurement facility for UWB antennas employing a hardware gating technique

2010 ◽  
Vol 8 ◽  
pp. 243-250 ◽  
Author(s):  
M. D. Blech ◽  
M. M. Leibfritz ◽  
R. Hellinger ◽  
D. Geier ◽  
F. A. Maier ◽  
...  
Keyword(s):  
Time Domain ◽  
Pulse Generator ◽  
Low Cost ◽  
Near Field ◽  
Ultra Wideband ◽  
Time Interval ◽  
Measurement Facility ◽  
Antenna Measurement ◽  
Uwb Antennas ◽  
Equivalent Time

Abstract. A spherical near-field antenna measurement facility employing a time domain hardware gating technique is presented. On-off keyed sinusoidal impulses are used as stimuli requiring wideband antennas with a bandwidth in excess of 400 MHz. The received signal is evaluated in the time interval after reaching the steady state and before multipath components arising in the non-ideal anechoic chamber distort the signal. An application specific pulse generator synthesizing sinusoidal impulses with a sub-nanosecond settling time and a low-cost equivalent time (ET) sampling receiver developed and optimized for this particular purpose are described. Measurement results of typical ultra-wideband (UWB) antennas show a significant improvement of the measured antenna pattern compared to conventional techniques.

Frequency and time domain hybrid optical memory

1993 ◽  
Author(s):  
Yu S. Bai ◽  
Xiao A. Shen ◽  
Ravinder Kachru
Keyword(s):  
Time Domain ◽  
Optical Memory

scholarly journals A Novel Position Domain Controller For Contour Tracking Performance Improvement

2021 ◽  
Author(s):  
Truong Dam
Keyword(s):  
Time Domain ◽  
Phase Error ◽  
Common Factor ◽  
Tracking Error ◽  
Numerical Control ◽  
Tracking Performance ◽  
Contour Error ◽  
Contour Tracking ◽  
Cnc Machine ◽  
Equivalent Time

A common problem with modern manufacturing processes that utilize high feed-rate machining is how to accurately track a given contour for the tool center point (TCP) of a system. Various methods have been developed to increase axial tracking performance and contouring performance of computerized numerical control (CNC) machines. These include: high gain feedback controllers, feedforward controllers, zero phase error tracking controllers (ZPETC), cross-coupled control (CCC), and iterative learning control to mention a few. The common factor amongst these methods is that they are all based in time domain. This thesis will propose a new control law based in position domain applied to contour tracking control of a CNC machine. The goal of this developed controller is to improve the overall tracking and contouring performance of a CNC system. The idea behind a position domain control involves transforming the dynamics of a system from time domain into position domain through a one-to-one mapping. In the position domain system control, the motion of one of the axis is used as an independent reference by sampling equidistantly to control the remaining axes according to the contouring requirements. The overall contour error in a position domain controller should be lower relative to an equivalent time domain controller since there will be a zero tracking error from the reference motion. The stability of the proposed position domain control is proven through the Lyapunov method. Simulations with linear and nonlinear TCP contours using the proposed position domain controller and an equivalent time domain controller indicate that the proposed position domain control can improve tracking and contouring performance. In addition, a position domain controller with cross-coupled control was also proposed to further improve contour performance.

Equivalent time domain procedures for bispectral analysis

1990 ◽  
Vol 137 (1) ◽  
pp. 131-134 ◽  
Author(s):  
J.A. Fitzpatrick ◽  
H.J. Rice
Keyword(s):  
Time Domain ◽  
Bispectral Analysis ◽  
Equivalent Time
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