淘宝官方店推荐课程在线工具联系方式关于我们

	微波射频仿真设计 Ansoft Designer 中文培训教程 \| HFSS视频培训教程套装
	Agilent ADS 视频培训教程 \| CST微波工作室视频教程 \| AWR Microwave Office

首页 >> Ansoft Designer >> Ansoft Designer在线帮助文档

Ansoft Designer / Ansys Designer 在线帮助文档：

Nexxim Simulator >
Nexxim Component Models >
Probes >
Time Domain Reflectometer

Time Domain Reflectometer

Time Domain Reflectometer Netlist Format

The Time Domain Reflectometer (TDR) isolates faults in long runs of inaccessible cables and transmission lines. A pulse is injected into the line and the reflections are captured in the time domain. The fault location is determined from the timing of the reflections and the propagation delay in the channel.

The result at the TDR is a graph of impedance vs. time. The data are available in the Report dialog under the Device Properties category. For the single-ended TDR, the report shows the reflected impedance vs. time. For the differential TDR, the data can show the impedance at the positive node, the impedance at the negative node, and the impedance difference between the two nodes.

The netlist syntax for the single-ended TDR is:

ATDRxxxx n1 COMPONENT=TDR_Single_Ended RISE_TIME=val PULSE_WIDTH=val PULSE_REPETITION=val TIME_DELAY=val Z0=val

.PRINT TRAN V(ATDRxxxx) O(ATDRxxxx,zl)

n1 is the node connected to the single-ended TDR. The entry COMPONENT=TDR_Single_Ended identifies the element. The .PRINT line generates the output data.

The netlist syntax for the differential TDR is:

ATDRxxxx positive negative COMPONENT=TDR_Differential_Ended RISE_TIME=val PULSE_WIDTH=val PULSE_REPETITION=val TIME_DELAY=val Z0=val

.PRINT TRAN V(ATDRxxxx) O(ATDRxxxx,zpos) O(ATDRxxxx,zneg) O(ATDRxxxx,zdiff)

Positive and negative are the nodes connected to the differential TDR. The entry COMPONENT=TDR_Differential_Ended identifies the element. The .PRINT line generates the output data.

**TDR Parameters**
Parameter	Description	Unit	Default
RISE_TIME	Rise time for voltage pulse	Sec	35e-6
PULSE_WIDTH	Width of voltage pulse	Sec	1e-5
PULSE_REPETITION	Period of repetition for the voltage pulse	Sec	2e-5
TIME_DELAY	Delay before pulse	Sec	5e-10
Z0	Characteristic impedance	Ohm	50

Time Domain Reflectometer Netlist Examples

ATDR1 net_34 COMPONENT=TDR_Single_Ended
+ RISE_TIME=25e-6 PULSE_WIDTH=5e-6 PULSE_REPETITION=1e-5

.PRINT TRAN V(ATDR1) O(ATDR1,zl)

ATDR110 net_34 COMPONENT=TDR_Differential_Ended
+ RISE_TIME=25e-6 PULSE_WIDTH=5e-6 PULSE_REPETITION=1e-5

.PRINT TRAN V(ATDR110) O(ATDR110,zpos) O(ATDR110,zneg)
+ O(ATDR110,zdiff)

HFSS视频教程 ADS视频教程 CST视频教程 Ansoft Designer 中文教程


Copyright © 2006 - 2013 微波EDA网, All Rights Reserved 业务联系：mweda@163.com