Capacitively Coupled Ground Probe for TDR
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-02
An easily manipulated probe for determining circuit line integrity time domain reflectometry (TDR) uses the center conductor of a rigid coaxial cable as the signal contact and pear-shaped plate connected to the outer conductor as the ground probe contact. The ground probe can then be capacitively coupled to a larger ground reference panel. Referring to the figure, rigid coaxial cable 1 has an inner conductor 2 serving as signal contact for placement on a circuit line 3 to be tested on panel 4. Outer conductor 5 is connected by short lead 6 to a pear-shaped ground probe of copper foil 7 on an insulative substrate 8. Panel 4 may have conductors on the opposite side and is supported on a ground reference plane of substrate 9 and the copper foil 10.