[SI-LIST] The crosstalk of transmission line when it is completely matched
- From: Zhangkun <zhang_kun@xxxxxxxxxx>
- To: si-list <si-list@xxxxxxxxxxxxx>
- Date: Fri, 06 Dec 2002 11:21:50 +0800
Hi all:
This morning, I do some crosstalk simulation. I find something interesting. The
following is what I do.
1. Create diffline.rlgc from rlgc.sp
2. Calculate the Z_diff and Z_comm from diffline.rlgc
3. Match the diffline and simulate it by match_2.sp
I find the near end crosstalk and the far end crosstalk are equal. This is not
same to the general crosstalk theory. I want to know why.
rlgc.sp
.OPTION PROBE POST
VIMPULSE in1 gnd PULSE 0v 5v 5n 2n 2n 20n
W1 in1 in2 gnd out1 out2 gnd FSmodel=cond2_sys N=2 l=1000mil
Rin2 in2 gnd 49
Rout1 out1 gnd 49
Rout2 out2 gnd 49
.MATERIAL diel DIELECTRIC ER=4.5
.SHAPE rect RECTANGLE WIDTH=7mil, HEIGHT=2mil,
.LAYERSTACK stack1,
+LAYER=(PEC,20mil), LAYER=(diel,22mil),
+LAYER=(PEC,20mil)
.FSOPTIONS opt1 PRINTDATA=YES
.MODEL cond2_sys W MODELTYPE=FieldSolver,
+LAYERSTACK=stack1, FSOPTIONS=opt1
+RLGCFILE=diffline.rlgc
+CONDUCTOR=(SHAPE=rect, ORIGIN=(0,30mil)),
+CONDUCTOR=(SHAPE=rect, ORIGIN=(14mil,30mil))
.TRAN 0.5n 100n
.PROBE v(out1)
.END
diffline.sp
*SYSTEM_NAME : cond2_sys
*
* ------------------------------------ Z = 0.0015748
* //// Top Ground Plane //////////////
* ------------------------------------ Z = 0.0010668
* diel H = 0.0005588
* ------------------------------------ Z = 0.000508
* //// Bottom Ground Plane ///////////
* ------------------------------------ Z = 0
* N (number of signal conductors)
*********************************
2
* Lo (H/m)
*********************************
3.42622e-07
6.40120e-08 3.42622e-07
* Co (F/m)
*********************************
1.50678e-10
-2.82540e-11 1.50678e-10
* Ro (Ohms/m)
*********************************
0.00000e+00
0.00000e+00 0.00000e+00
* Go (S/m)
*********************************
0.00000e+00
-0.00000e+00 0.00000e+00
match_2.sp
the simple diff transmissionline
.options list node post
.op
.tran 0.5n 100n
*driver
vp in1 gnd pulse 0 5 1n 1n 1n 3n 8n
*vn in2 gnd pulse 10 0 1n 1n 1n 3n 8n
rin2 in2 gnd 47.69
*transmission line
Wcable in1 in2 gnd out1 out2 gnd RLGCfile=diffline.rlgc n=2 l=5000mil
*receiver
rout1 out1 node1 39.4598
rout2 out2 node1 39.4598
rcon node1 gnd 9.0864
.end
Z_diff=78.9195 Z_comm=28.8163
rou1=rout2=Z_diff/2
rcon=(2*Z_comm-Z_diff/2)/2
Best Regards
Zhangkun
2002.12.06
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
- » [SI-LIST] The crosstalk of transmission line when it is completely matched
