WN2A - 2008-12-19

Greetings QUCS community:
 
I have been using ASCO with QUCS successfully in many simulations, but  very often see a tough problem when optimizing microstrip dimensions (and sometimes theoretical transmission line dimensions). The error message reads:

"asco.c Value is zero when using DE in emulated local mode."

Asco will then terminate.

OS : Puppy Linux 4.0 with qucs-0-0-14.pet installed. Asco was installed with qucs in same /usr/local/bin directory. (See my site):

    http://wn2a73.googlepages.com/qucs.html

For all other qucs components that I have used, no optimizer problems.
Works very well with everything else I have seen. When one disables the optimizer(Opt2) and enables the equation block (Eqn3), the circuit will perform as expected.

Could someone provide me with some direction? I realize this is probably an ASCO issue, not QUCS, but this forum has several ASCO users.

The schematic file is listed here:

<Qucs Schematic 0.0.14>
<Properties>
  <View=816,68,1761,714,1,0,60>
  <Grid=10,10,1>
  <DataSet=MLIN_Opt_B.dat>
  <DataDisplay=MLIN_Opt_B.dpl>
  <OpenDisplay=0>
  <showFrame=0>
  <FrameText0=Title>
  <FrameText1=Drawn By:>
  <FrameText2=Date:>
  <FrameText3=Revision:>
</Properties>
<Symbol>
</Symbol>
<Components>
  <Pac P2 1 1090 320 18 -26 0 1 "2" 1 "50 Ohm" 1 "0 dBm" 0 "1 GHz" 0 "26.85" 0>
  <GND * 1 1090 350 0 0 0 0>
  <Pac P1 1 870 320 18 -26 0 1 "1" 1 "50 Ohm" 1 "0 dBm" 0 "1 GHz" 0 "26.85" 0>
  <GND * 1 870 350 0 0 0 0>
  <MLIN MS1 1 980 250 -26 15 0 0 "Subst1" 1 "W" 1 "L" 1 "Hammerstad" 0 "Kirschning" 0 "26.85" 0>
  <SUBST Subst1 1 1310 480 -30 24 0 0 "2.94" 1 ".254e-3" 1 ".1e-3" 1 ".001" 1 "0.022e-6" 1 "1.4e-6" 1>
  <Eqn Eqn1 1 880 410 -22 16 0 0 "dB_S21=dB(S[2,1])" 1 "dB_S12=dB(S[1,2])" 1 "dB_S11=dB(S[1,1])" 1 "dB_S22=dB(S[2,2])" 1 "yes" 0>
  <Eqn Eqn2 1 1030 420 -24 14 0 0 "Max_dB_S11=max(dB(S[1,1]))" 1 "Max_dB_S22=max(dB(S[2,2]))" 1 "Min_dB_S21=min(dB(S[2,1]))" 1 "yes" 0>
  <.Opt Opt2 1 1400 200 0 33 0 0 "Sim=SP1" 0 "DE=3|100|2|20|0.85|1|3|1e-6|10|100" 0 "Var=L|yes|.01|.001|.5|LIN_DOUBLE" 0 "Var=W|yes|.0007|.0001|.001|LIN_DOUBLE" 0 "Goal=Max_dB_S11|LE|-27" 0 "Goal=Min_dB_S21|EQ|-1" 0>
  <.SP SP1 1 1250 200 0 89 0 0 "lin" 1 "2000MHz" 1 "4000MHz" 1 "51" 1 "no" 0 "1" 0 "2" 0 "no" 0 "no" 0>
  <Eqn Eqn3 0 1430 270 -24 14 0 0 "W=.0006" 1 "L=.132" 1 "yes" 0>
</Components>
<Wires>
  <1090 250 1090 290 "" 0 0 0 "">
  <1010 250 1090 250 "" 0 0 0 "">
  <870 250 870 290 "" 0 0 0 "">
  <870 250 950 250 "" 0 0 0 "">
</Wires>
<Diagrams>
  <Rect 1460 570 294 200 3 #c0c0c0 1 00 1 0 0.2 1 1 -0.1 0.5 1.1 1 -0.1 0.5 1.1 315 0 225 "" "" "">
    <"dB_S21" #0000ff 0 3 0 0 0>
    <"dB_S11" #ff0000 0 3 0 0 0>
  </Rect>
  <Tab 840 576 388 56 3 #c0c0c0 1 00 1 0 1 1 1 0 1 1 1 0 1 1 315 0 225 "" "" "">
    <"Max_dB_S11" #0000ff 0 3 1 0 0>
    <"Max_dB_S22" #0000ff 0 3 1 0 0>
    <"Min_dB_S21" #0000ff 0 3 1 0 0>
  </Tab>
</Diagrams>
<Paintings>
</Paintings>

Thank You!!!
WN2A