Multi-Mix® Application Notes

Simulated Via Performance

Below are the results of the simulation for the via structure used in our MultiMix® technology. The simulation was performed using "Micro-Stripes 3.0". Micro-Stripes 3.0 is a full 3-dimensional electromagnetic field simulator. The software is based upon the Transmission-Line Modeling Method (TLM) and calculates the impulse response of a device.

The via that was simulated is a 0.008 inch diameter that travels through two 0.010 inch thick substrates. There is a long length of 50 ohm transmission line on either side of the via structure. This line length is included in the insertion loss and insertion phase responses. This is the MultiMix® high frequency via structure and therefore, the simulated results are shown starting at 10 through 50 GHz.

Shown in Figure 1 is the simulated insertion loss of a single via. The data indicates that the insertion loss of the via and length of transmission line is below 0.50 dB loss through 40 GHz and the worst case insertion loss is only 0.53 dB at 47 GHz. The shape of the insertion loss plot indicated that the structure is mode free through 50 GHz.

Shown in Figure 2 is the phase response of the high frequency via structure. Here again, the shape of the response indicates mode free operation through 50 GHz.

Figure 1. Insertion loss of MultiMix® high frequency via with input and output transmission line.

Figure 2. Insertion phase of MultiMix® high frequency via with input and output transmission lines.

Shown in Figure 3 of this report is the return loss of the high frequency via structure of the MultiMix® technology. Again, the smooth shape of the plot indicates that the via structure is mode free through 50 GHz and that the via and long length of transmission line has 20 dB return loss at 30 GHz and 16 dB return loss at 50 GHz.

Figure 3. Return loss of the high frequency via structure used in Multi-Mix®.

This via structure is presently being fabricated and the test results will be presented as soon as they are available. Meanwhile, work continues to improve the via structure to provide mode free low loss connections between layers beyond 77GHz.