Design

It is time to put these equations to work by computing the radiation from a simple structure, a short wire element.

In the preceding chapters we have derived Maxwell’s Equations and expressed them in their “integral” and “differential” form. In different ways, both forms lend themselves to a certain intuitive understanding of the nature of electromagnetic fields and waves. In this installment, we will express Maxwell’s Equations in their “computational form,” a form that allows our computers to do the work.

This paper describes how to remove the measurement artifacts caused by discontinuities in high frequency S-parameter data caused by the test connectors on the Printed Circuit Boards (PCBs) and cables. The frequency domain S-parameters are converted to the time domain to get the impulse response. Time domain gating is then used on this impulse response to remove reflections due to end connectors and/or other discontinuities. The gated impulse response is then transformed back to the frequency domain. The final result is a much improved S-parameter data set with unwanted resonance removed, allowing the PCB trace or cable loss to be determined.