Using Coupled Transmission Lines to Generate Impedance-Matched Pulses Resembling Charged Device Model ESD

A quarter-wave directional coupler plus ordinary transmission line pulsing (TLP) can create short pulses resembling charged device model (CDM) electrostatic discharge (ESD). Pulse rise time often relates to the coupler's center frequency and can thereby be stabilized. It is shown that for a voltage step of a given size, yet with arbitrary waveform, the net amount of coupled charge (the charge packet) is constant and depends only on fixed coupler parameters. This property of Z-matched coupled lines has wider implications. High-voltage couplers can be made from coaxial cable or from stripline. Some of these designs are described, tested, and compared to computer simulations of coupled lines