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Design Languages >> VHDL-AMS >> solving transmission line in VHDL-AMS
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Message started by abra on Mar 24^th, 2010, 2:29am

Title: solving transmission line in VHDL-AMS
Post by abra on Mar 24^th, 2010, 2:29am

Dear Expert,

I need an advice for the following codes for transmission line model example. I can compile it, but i will not get any result. Something missing perhaps

.........................................................

architecture bhv of transmission_line is
constant Lz : real :=1.0;
constant Cz : real :=1.0;
constant Lenght : real :=1.0;
constant N : real :=5.0;
constant dz : real :=Lenght/N;
constant C : real :=Lz*dz;
constant L : real :=Cz*dz;
constant Zs : real :=1.0;
constant ZL : real :=1.0;
constant Vs : real :=5.0;

quantity Vin across Iin through a to g;
quantity Vout across Iout through b to g;
quantity V1,V2,V3,V4 : real;
quantity I2,I3,I4,I5 : real;

begin

-(V1-Vin) == L*Iin'dot;
-(I2-Iin) == C*V1'dot;
-(V2-V1) == L*I2'dot;
...
-(I5-I4) == C*V4'dot;
-(Vout-V4) == L*I5'dot;
-(Iout-I5) == C*Vout'dot;

end architecture bhv;

and, when I add inteface condition, I will get "too many equation, ambiguous model".

Vin == Vs - Iin*Zs;
Vout == Iout*ZL;

Thanks in advance

Title: Re: solving transmission line in VHDL-AMS
Post by Andrew Beckett on Apr 11^th, 2010, 1:01pm

Can you give the entity and perhaps a block which is using the transmission line model?

I'm sure I could guess and put something together, but it would take less time to take whatever you have already...

Regards,

Andrew.