POWER BUDGET ?? >> PCB problem

The problem presented by Ben Hadj (see below) is typical for PCB lay-out
We can see why NEC may have difficulties: Some wires cross at very close
distance (e.g. wires 5 and 6) and wires with small segments are connected
to wires with long segments (e.g. wires 27-28-29).
In my experience, the best solution is to use another interaction kernel
than the one in NEC. Does anyone else have experience with printed circuits
modelling using NEC?

Jos Bergervoet

Reference: R. du Cloux, W. de Graaf, G. Maas, R. vd Veeken, EMC simulations
           and measurements, Proc. 11th Zurich EMC symposium, 1995

PS: David de Schweinitz's viewer (NV.EXE) is very usefull for inspecting
    this kind of input files. You do need, however, to add commas after
    each GW and GE keyword!

>
> Dear netters,
>
> I'm using NEC2 to calculate the Electricfield radiated by a PCB card.
>
> in the output file, the POWER BUDGET is :
>
> - - - POWER BUDGET - - -
>
> INPUT POWER = 4.2950E-07 WATTS
> RADIATED POWER=-1.8011E-06 WATTS
> STRUCTURE LOSS= 2.2306E-06 WATTS
> NETWORK LOSS = 0.0000E+00 WATTS
> EFFICIENCY =-419.36 PERCENT
>
>
>
> so there is a negative RADIATED POWER and the EFFICIENCY =-419.36 PERCENT
>
> could anyone explain me what that means, and say me if that is normal
>
>
> Thanks in advance,
>
> the input file is :
> //////////////////////////////////////////////////////////////////////
>
> CM BEN HADJ SLAMA J.
> CM CARTE HACHEUR A COMMUTATION FORCEE f=2.5e5
> CM carte a 20mm du plan de masse, point de mesure 0,-1 ,0.80
> CM
> CE FICHIER FORCE1
> GW 1 3,0.,0.1,0.02,0,0.072,0.02,0.001
> GW 2 3,0.,0.072,0.02,0.025,0.072,0.02,0.001
> GW 3 5,0.025,0.072,0.02,0.075,0.072,0.02,0.001
> GW 4 4,0.075,0.072,0.02,0.075,0.039,0.02,0.001
> GW 5 9,0.075,0.039,0.02,-0.015,0.039,0.019,0.001
> GW 6 4,0.003,0.072,0.02,0.003,0.03,0.02,0.001
> GW 7 3,0.003,0.03,0.02,0.003,0.03,0.002,0.001
> GW 8 3,0.003,0.03,0.002,-0.015,0.03,0.002,0.001
> GW 9 3,-0.015,0.03,0.002,-0.015,0.039,0.019,0.001
> GW 10 3,0.003,0.03,0.02,-0.027,0.03,0.02,0.001
> GW 11 2,-0.027,0.03,0.02,-0.027,0.015,0.02,0.001
> GW 12 3,-0.027,0.015,0.02,-0.055,0.015,0.02,0.001
> GW 13 2,-0.055,0.015,0.02,-0.055,0.034,0.02,0.001
> GW 14 4,-0.055,0.034,0.02,-0.015,0.039,0.019,0.001
> GW 15 6,-0.027,0.015,0.02,-0.085,0.015,0.02,0.001
> GW 16 5,-0.085,0.015,0.02,-0.085,0.065,0.021,0.001
> GW 17 6,-0.062,0.034,0.02,-0.062,0.097,0.02,0.001
> GW 18 2,-0.055,0.034,0.02,-0.062,0.034,0.02,0.001
> GW 19 3,-0.062,0.034,0.02,-0.085,0.034,0.02,0.001
> GW 20 3,-0.085,0.034,0.02,-0.085,0.065,0.021,0.001
> GW 21 3,-0.085,0.065,0.021,-0.062,0.097,0.02,0.001
> GW 22 5,-0.062,0.097,0.02,-0.01,0.097,0.02,0.001
> GW 23 3,-0.01,0.097,0.02,-0.01,0.097,0.002,0.001
> GW 24 3,-0.01,0.097,0.002,0,0.097,0.002,0.001
> GW 25 3,0,0.097,0.002,0,0.1,0.02,0.001
> GW 26 3,0,0.1,0.02,0.025,0.1,0.02,0.001
> GW 27 7,0.025,0.1,0.02,0.095,0.1,0.02,0.001
> GW 28 3,0.095,0.1,0.02,0.095,0.097,0.019,0.001
> GW 29 8,0.095,0.097,0.019,-0.01,0.097,0.02,0.001
> GW 30 3,0.025,0.072,0.02,0.025,0.1,0.02,0.001
> GW 31 6,0.075,0.039,0.02,0.075,0.039,0,0.001
> GE 1
> PL 2 2 4
> FR 0 1 0 0 9.99e+01
> EX 5 2 2 00 3.11e-02 4.69e-04
> EX 5 8 2 00 3.12e-03 2.29e-05
> EX 5 10 2 00 2.84e-02 3.74e-04
> EX 5 24 2 00 -2.96e-04 -8.92e-06
> LD 0 1 1 3 0 2.e-6
> LD 0 3 1 3 0 0 1.e-8
> LD 0 14 1 4 0 0 14.e-8
> LD 0 16 2 4 33.
> LD 0 17 2 4 0 0 1.e-5
> LD 0 30 1 3 15.
> GN 1 1
> PT -1
> NE 0 1 1 1 0. -1. 0.8
> XQ
> EN
>
> ///////////////////////////////////////////////
>
>
>
>
> --
> *****************************************************************************
> BEN HADJ SLAMA Jaleleddine
> CEGELY-ECL
> 36, Av Guy de collongue BP 163
> 69131 Ecully cedex FRANCE
> Tel:72.18.61.05 Fax:78.33.43.17
> email: slama_at_trotek.ec-lyon.fr
> slama_at_cc.ec-lyon.fr
> ******************************************************************************
>
>
Received on Tue Apr 16 1996 - 16:53:00 EDT