Doubts on Circuit Simulation and EM(electromagnetic)Simulation

[hari_preetha]

Sir,
1)What is the difference between Circuit Simulation and EM(ElectroMagnetic)Simulation
2) When we are going for EM simulation
3) What is the use of EM Simulation
4) Can we do EM simulation for circuit contains both passive and active elements
5) Why can't we do EM simulation, if circuit contains both passive and active elements
6) Why we go EM simulation, if circuit contains only MLIN's and passive components

 

[volker@muehlhaus]

1)What is the difference between Circuit Simulation and EM(ElectroMagnetic)Simulation

Circuit simulation is based on many small blockes, and signal flow is only through the drawn connections between the blocks. Inside a block, there might be some coupling included (e.g. model for two coupled lines) but there is no other coupling between the blocks. If you have two blocks with a single line, the coupling between the lines is not included. The signal between blocks is only through the connections (wires) that you draw between the blocks.

2) When we are going for EM simulation
3) What is the use of EM Simulation

We can use circuit models for simple layout elements (line, tee, cross, ...)
We use EM when coupling between blocks is important, or where we have no good models for complex layouts.
EM gives accurate S-parameters for any layout, with no need for a circuit model.

4) Can we do EM simulation for circuit contains both passive and active elements
5) Why can't we do EM simulation, if circuit contains both passive and active elements

Technically, the EM simulation is only done on the layout. This results in S-parameters for the layout without devices. The devices are then connected at the ports and the overall circuit is simulated.

6) Why we go EM simulation, if circuit contains only MLIN's and passive components

We use EM when coupling between blocks is important, or where we have no good models for complex layouts, or where we have extreme geometries outside the model range. EM gives accurate S-parameters for any layout, with no need for a circuit model.

 

[hari_preetha]

Technically, the EM simulation is only done on the layout. This results in S-parameters for the layout without devices. The devices are then connected at the ports and the overall circuit is simulated.

Sir,
If layout has both passive(SMT capacitors, resistors, and inductors) and active components(transistors). Is it possible for EM simulation.
In ADS2009 and ADS2011, if layout contains both passive and active components. It is not possible for EM simulation.

 

[BigBoss]

Sir,
If layout has both passive(SMT capacitors, resistors, and inductors) and active components(transistors). Is it possible for EM simulation.
In ADS2009 and ADS2011, if layout contains both passive and active components. It is not possible for EM simulation.

EM simulations are always done with passive layout elements (PCB, Laminate,Silicon etc) to compute the s-parameters.You can not do EM simulation with active/passive components in ADS .If you intend to add these components, you should do " EM Circuit Co-Simulation" to get other simulation results ( HB,AC,S,DC,Tran.etc.)

Note: Sonnet is able to do simulations active and passive circuits on small signal linear level (e.g. s-parameters).

 

[volker@muehlhaus]

If layout has both passive(SMT capacitors, resistors, and inductors) and active components(transistors). Is it possible for EM simulation.

Please read what I wrote above. :???:

The actual EM simulation does ONLY the layout part, but the software offers co-simulation where the EM results are then combined with components. Combining is done at circuit simulation level, which means that it can be active or passive devices.

In ADS2009 and ADS2011, if layout contains both passive and active components. It is not possible for EM simulation.

You need to study the ADS co-simulation workflow.

Note: Sonnet is able to do simulations active and passive circuits on small signal linear level (e.g. s-parameters).

Sonnet does the co-simulation behind the scenes, so we define the components in the Sonnet editor. But technically, again, it is EM simulation followed by circuit simulation to connect the devices.

 

[hari_preetha]

You can not do EM simulation with active/passive components in ADS .If you intend to add these components, you should do " EM Circuit Co-Simulation" to get other simulation results ( HB,AC,S,DC,Tran.etc.)

Note: Sonnet is able to do simulations active and passive circuits on small signal linear level (e.g. s-parameters).

Sir,
I read somewhere, using ADS2014 other than Sonnet, it is possible to do EM simulation of layout, even though layout contains both passive and active components. It is possible,can you clarify it.

 

[volker@muehlhaus]

Sir,
I read somewhere, using ADS2014 other than Sonnet, it is possible to do EM simulation of layout, even though layout contains both passive and active components. It is possible,can you clarify it.

It depends what you define as "EM simulation". Technically, as already mentioned many times, the EM simulation includes the layout and nothing else. All the components are connected through ports, in a post-EM circuit simulation. What is implemented in ADS 2014 helps to set up this co-simulation more easily.

 

[hari_preetha]

The signal between blocks is only through the connections (wires) that you draw between the blocks.

Sir,
Whenever RF signal flow through the MLIN, there must be effect of electric field( which originates from +ve and terminate it on the -ve) and magnetic field(around the conductor). Are these EM effects (EM field) are included in the EM simulation ,can you clarify it.
In the circuit simulation, whenever signal flowing through the MLIN, are EM effects included at the end result of s-parameter simulation.
What is prime use of circuit simulation and EM simulation.

 

[BigBoss]

Sir,
I read somewhere, using ADS2014 other than Sonnet, it is possible to do EM simulation of layout, even though layout contains both passive and active components. It is possible,can you clarify it.

ADS Momentum cannot recognize neither passive nor active components.It recognizes only the substrate and metal layers.That's it..
In order to connect these active and passive components, you must create a seperate schematic view, transfer your EM Simulated layout with associated pins that will be connected to passive and active parts and then you have to do other simulations ( AC,DC,Trans. etc) in this seperate schematic view.
Is that clear ??

 

[volker@muehlhaus]

Whenever RF signal flow through the MLIN, there must be effect of electric field( which originates from +ve and terminate it on the -ve) and magnetic field(around the conductor).

MLIN is a special case, because it is layout (=> can be EM simulated) but ADS also has a circuit model for this layout (for one single line). If you just have one single MLIN that does not couple with other MLINs, the circuit model results is ok. If you have multiple MLIN which are near, and couple, that coupling is not included in the circuit models. In this case, you need EM which includes all effects and all coupling in the layout.

In the circuit simulation, whenever signal flowing through the MLIN, are EM effects included at the end result of s-parameter simulation.

Yes, sure.