With fast advances of digital electronics in microwave frequency band there is a growing interest in the possibility to watch signals directly in the time domain like it is done in a measurement technique called Time Domain Reflectometry (TDR).
TDR-like signals can be extracted directly from QW-3D simulations. We will explain such a possibility using a simple example tdr1.pro. This example has been drawn using especially prepared tdr1.udo, which is a simple script composed entirely of calls to other objects available in standard QW-3D libraries. It contains a strip-line structure shown in Fig.1.
Fig.1. Structure considered in the example tdr1.pro.
Actually, we are considering a lower half of the structure assuming a magnetic symmetry plane. Substrate is a 6 mm thick teflon. The input strip is 1 mm thick, 3.5 mm wide, and 32 mm long. It is terminated by a grounded strip of width 0.5 mm. During the simulation the structure will be excited by a step pulse and we will be considering Ezand Hy fields below the strip, at the point situated 3.36 mm from the input and thus 28.64 mm from the end of the wide strip.
Fig.2. Ez and Hy field versus time obtained in tdr1.pro example.