Equivalent-time sampling is a well-known technique to capture repetitive signals at finer time intervals than a sampling clock cycle time and it is widely used to implement waveform measurement with high time resolution. There are three techniques for implementing its time base (i.e., sequential sampling, random sampling and coherent sampling), and they have their respective advantages and disadvantages. In this paper we propose a new coherent sampling system which incorporates a pretrigger and time jitter reduction function for a fluctuating input signal which a random sampling system has, while maintaining the waveform recording efficiency of a conventional coherent sampling system. We also report on a technique for measuring a reference trigger time period accurately which is necessary to implement the proposed sampling system, and show its effectiveness through numerical calculations of its data recording time.

This paper proposes a quasi-coherent equivalent-time sampling method to acquire repetitive wideband waveform signals with high throughput. We have already proposed a new sampling system which incorporates the pre-trigger ability and the time jitter reduction function for a fluctuated input signal while maintaining the waveform recording efficiency. The quasi-coherent sampling method proposed in this paper can be adopted to it in order to improve its data acquisition throughput significantly. Numerical simulation results show effectiveness of our proposed method.

Copper strips plated with Sn-Pb eutectic solder were hot pressure-bonded to gold thin-film wiring. It was proven that a Au-Sn alloy forms at the interconnection between the gold thin film and the copper strip, but that there is virtually no Pb present in the interconnection. Au, Sn, and Pb were observed on the surfaces of the copper strips and the gold thin film outside of the connection area.