Below is the geometry that i am simulating in 3D EM solver in hyperlynx.

**PROBLEM: While simulating insertion and return loss plots are reversed.**

**INSERTION LOSS**

**RETURN LOSS**

Can anyone help why it is happening.

Below is the geometry that i am simulating in 3D EM solver in hyperlynx.

**PROBLEM: While simulating insertion and return loss plots are reversed.**

**INSERTION LOSS**

**RETURN LOSS**

Can anyone help why it is happening.

**Thanks for the reply.**I have a confusion, capacitor will act as an open circuit in low frequency and short circuit at high frequency, so while extracting in 3D em in port creation wizard , i gave open circuit for capacitors to neglect the creation of ports .

Can you please explain how 3D field solver will take capacitor effects into considerations.

The 3d solver in HL9.2 would not take it into consideration. it was one of its limitations. A second step outside of the 3d solver was required in linesim to connect ports on the pads of the capacitor (open in the 3d solver) with a capacitor and extract an s parameter model for the whole linesim schematic.

The new solver in HL 9.3 can use capacitors directly during solve.

**Thanks for the reply****Below is the 3-D geometry****As said by you****I generated scattering parameters for the above geometry.**scattering parameters generated by above geometry were taken into line-sim to introduce the effect of ac coupling capacitors and then i saw

**insertion and return loss profile**I took capacitor as 100nF and shorted it with resistor od

**But whether i take capacitor as 100 nF or remove that capacitor with 0 ohms same graph was observed for return and insertion loss, i think in line-sim also it is not taking capacitor into consideration.****Can you help me with this?**

The ac capacitor adds an open at DC to the signals. Thats why IL starts very low in the negative dB (no energy comes through close to DC) and RL starts close to zero (most of the energy gets reflected close to DC).