Question

If a voltage pulse of height v0 is moving toward an impedence

Answer 1

between the preamp and the detector, and is used for both high voltage bias to the detector and signal .... produces a logic output pulse only when the linear input pulse height exceeds a threshold, i.e. discriminator ...

Answer 2

We previously quickly discussed signal reflection in our PCB transmission line article. This is an in-depth article about this very important topic that PCB designers should master. The first thing to remember is that signal reflection in PCB transmission lines occurs due to impedance discontinuity.

A transmission line should have a uniform characteristic impedance. Any variation or discontinuities to the impedance causes signal reflection and distortion.

This phenomenon is equally true for PCB traces and transmission lines. The reason for this is that the physical wavelength of a high-frequency signal is very short. For that reason, PCB traces exhibit the same characteristics. The higher the frequency, the shorter the wavelength. You must even treat shorter traces like transmission lines.

Signal trace discontinuities or non-uniform discontinuities form signal integrity discontinuities. In order to avoid signal distortion at the source and destination, you must match the PCB trace impedance to source. You must then load impedance at the source and destination ends. This presents a considerable challenge that requires careful PCB design to mitigate the effects of signal degradation caused by impedance discontinuity. The greater the discontinuity in the characteristic impedance, the higher the signal reflection. This means the signal distortion is higher as well. As such, try and keep impedance discontinuities as minimal as possible. Both in terms of amplitude and time.