A Time and Frequency Measurement Technique Based on Length Vernier

A simple length vernier approach has been developed which uses the high stability and high speed of signal transmission and the relation of time and space. It can get high resolution, low cost and simple structure. Based on high stable transmission delay of the signal and the coincidence detection technique, the start and stop signals of a measured short time interval are delayed respectively in the different lines. The line length to transmit the start signal is longer than that of the stop signal according to the measurement resolution, and both of the lines are divided into small subsections according to the measuring precision. Both active and passive device can be used for delay lines, but passive device can get higher resolution and has special problems that need be resolved. Based on the position of the coincidence between two signals, their delay difference can be used to express the measured time interval exactly. With this way, the measurement precision is much better than that of the unit subsection of the two delay lines for start and stop signals. This technique can show much finer than ns resolution and even better in the future. The different delay lines can be used here including coaxial cable, PC board, and even in integrated circuit