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16th June 2019, 22:01 #1
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Response of the TLINE for different frequencies and lengths
Hi,
1.I have tried to sweep the length of TLINE keeping frequency constant for the open circuit case and short circuit case but I don't really see the expected reactive behavior.
2.I have tried to sweep the Frequency of TLINE keeping length constant for the open circuit case and short circuit case but I don't really see the expected resonance behavior.

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16th June 2019, 22:19 #2
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Re: Response of the TLINE for different frequencies and lengths
I agree that the relation between electrical length and input impedance are presented correctly in the diagrams. You should be able to see in in a correct simulation setup. Unfortunately you neither show your simulation setup nor the results, which answers do you expect?

16th June 2019, 22:55 #3
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Re: Response of the TLINE for different frequencies and lengths
In the short circuit case, as I increase the length when 0<length<lambda/4, I expected to see inductive behavior and lambda/4<length<lambda/2, I expected to see capacitive behavior. And the same behavior should repeat again beyond lambda/2
In the open circuit case, as I increase the length when 0<length<lambda/4, I expected to see capacitive behavior and lambda/4<length<lambda/2, I expected to see inductive behavior.
I attached my test setup and results

16th June 2019, 23:14 #4
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Re: Response of the TLINE for different frequencies and lengths
You are sweeping "freq" variable ?? If it's so, you're doing a mistake because freq is not a variable for Cadence Spectre..
Instead, you should fix the frequency in sparameters simulation in Spectre ( single point) then change the Line Length.
Also, look at Zm ( Port Input Impedance ) instead of sparameters.

16th June 2019, 23:33 #5
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Re: Response of the TLINE for different frequencies and lengths
Exactly I did the same but you gave me one idea, I was not sweeping the frequency parameter in the TLINE. Should I need to do that to get its response against frequency or is sweeping the frequency in sparameter simulation enough?
What exactly happens when we do sparameter simulation, does it over write all other frequency variables in the schematic (in this case frequency parameter in TLINE component)?

16th June 2019, 23:57 #6

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17th June 2019, 00:21 #7
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17th June 2019, 01:12 #8

17th June 2019, 07:25 #9
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17th June 2019, 09:18 #10
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Re: Response of the TLINE for different frequencies and lengths

17th June 2019, 11:16 #11
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Re: Response of the TLINE for different frequencies and lengths
I use Synopsys HSPICE from Cadence ADE.
You may use ".LIN Analysis" instead of ".AC Analysis".
"test_circuitslave_1.spi"Code:** Generated for: hspiceD ** Generated on: Jun 17 11:47:47 2019 ** Design library name: My_RFDE_Test ** Design cell name: test_circuitslave ** Design view name: schematic .PARAM f0=1G nl0=0.25 .PROBE AC + I(v1) IP(v1) + I(v0) IP(v0) .AC LIN 1001 1e3 4e9 .TEMP 25.0 .OPTION + ACCURATE + ACOUT=0 + LIST=3 + ARTIST=2 + INGOLD=2 + INTERP + METHOD=GEAR + NOMOD + PARHIER=LOCAL + PROBE + PSF=2 + RUNLVL=6 ** Library name: My_RFDE_Test ** Cell name: test_circuitslave ** View name: schematic t1 net03 0 net02 0 ZO=50 F=f0 NL=nl0 IC=0 , 0 , 0 , 0 t0 net08 0 0 0 ZO=50 F=f0 NL=nl0 IC=0 , 0 , 0 , 0 v1 net03 0 AC 1 v0 net08 0 AC 1 .END
Code:simulator( 'hspiceD ) design( "/AHO/simulation/test_circuitslave/hspiceD/schematic/netlist/netlist" ) resultsDir( "/AHO/simulation/test_circuitslave/hspiceD/schematic" ) analysis('ac ?sweepType "linear" ?numPoints "1001" ?fstart "1e3" ?fstop "4G" ?points "1G" ) desVar( "f0" 1G ) desVar( "NL0" 0.25 ) option( 'TEMPDC "25.0" ) save( 'i "/V0/PLUS" "/V1/PLUS" ) temp( 25.0 ) run() Xin_short = imag((1 / getData("/i(v0)" ?result "frequencySweep"))) Xin_open = imag((1 / getData("/i(v1)" ?result "frequencySweep"))) plot( Xin_short ?expr '( "Xin_short" ) ) plot( Xin_open ?expr '( "Xin_open" ) )
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17th June 2019, 13:38 #12
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Re: Response of the TLINE for different frequencies and lengths
I used Cadence Spectre from Cadence ADE.
You may use "sp Analysis" instead of "ac Analysis".
"test_circuitslave_2.scs"Code:// Generated for: spectre // Generated on: Jun 17 11:59:19 2019 // Design library name: My_RFDE_Test // Design cell name: test_circuitslave // Design view name: schematic simulator lang=spectre global 0 parameters f0=1G NL0=0.25 // Library name: My_RFDE_Test // Cell name: test_circuitslave // View name: schematic T1 (net03 0 net02 0) tline z0=50 f=f0 nl=NL0 T0 (net08 0 0 0) tline z0=50 f=f0 nl=NL0 V1 (net03 0) vsource mag=1 type=dc V0 (net08 0) vsource mag=1 type=dc simulatorOptions options psfversion="1.1.0" reltol=1e3 vabstol=1e6 \ iabstol=1e12 temp=25.0 tnom=25.0 scalem=1.0 scale=1.0 gmin=1e12 \ rforce=1 maxnotes=5 maxwarns=5 digits=5 cols=80 pivrel=1e3 \ sensfile="../psf/sens.output" checklimitdest=psf ac ac freq=1G param=NL0 start=1e3 stop=1 lin=1001 save=all \ annotate=status save V0:p V1:p saveOptions options save=selected saveahdlvars=all
Code:simulator( 'spectre ) design( "/AHO/simulation/test_circuitslave/spectre/schematic/netlist/netlist" ) resultsDir( "/AHO/simulation/test_circuitslave/spectre/schematic" ) analysis('ac ?freq "1G" ?param "NL0" ?start "1e3" ?stop "1" ?lin "1001" ?dec "" ) desVar( "f0" 1G ) desVar( "NL0" 0.25 ) envOption( 'analysisOrder list("ac") ) save( 'i "/V0/PLUS" "/V1/PLUS" ) temp( 25.0 ) run() Xin_short = imag((1 / getData("/V0/PLUS" ?result "ac"))) Xin_open = imag((1 / getData("/V1/PLUS" ?result "ac"))) plot( Xin_short ?expr '( "Xin_short" ) ) plot( Xin_open ?expr '( "Xin_open" ) )
Any simulator can give same results.
Of course, LTspice have "tline".Last edited by pancho_hideboo; 17th June 2019 at 13:59.
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24th June 2019, 19:21 #13
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24th June 2019, 19:50 #14
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Re: Response of the TLINE for different frequencies and lengths
Last edited by pancho_hideboo; 24th June 2019 at 19:56.

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27th June 2019, 18:52 #15
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Re: Response of the TLINE for different frequencies and lengths

28th June 2019, 10:43 #16
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Re: Response of the TLINE for different frequencies and lengths
Nothing.
What do you want to mean ?
"basic/NoConn" is a symbol, that's all.
Compare Views of "analogLib/res" and "basic/NoConn".
And confirm cell property "nlAction" of "basic/NoConn".
Then consider and learn by yourself.
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