Agilent English 2013-02-11 PDF 713 KB 5991-1941EN c20140723 [9] free download

File name English _ 2013-02-11 _ PDF 713 KB 5991-1941EN c20140723 [9].pdf

Keysight Technologies Achieve High Speed, Multichannel Data Acquisition with the M9703A AXIe Digitizer Application Note Abstract In many multichannel high speed data acquisition ap- plications, such as radar, satellite (beam-forming), MIMO, or high-energy experiments, it is critical to have phase- coherent channels for accurate data acquisition whether for demodulation, antenna calibration, channel sounding, or event capture. Large-scale experiments may require the use of tens or hundreds of synchronized channels, and very precise time correlation between channels. Therefore, synchronization across multiple instruments is primordial. Figure 1. M9703A AXIe 12-bit digitizer and M9536A embedded AXIe controller in M9505A 5-slot chassis. This application note describes the measurement and analysis of cross channel skew in multichannel high speed digitizers over short and long durations to sub-pi- It is possible to achieve synchronous sampling across a cosecond scales. Two measurement techniques using the great number of acquisition channels, and measure the Keysight Technologies, Inc. M9703A High Speed Digitizer sub-nanosecond time delays between the samples of are described and compared, and the results presented. different channels3. Synchronous sampling means any two channels A and B acquiring data in synchronous sampling mode, where the ith voltage sample uAi is the measured Introduction signal voltage on channel A at time ti, there is a cor- responding sample uBj measured on channel B at time tj = ti High speed digitizer systems operating at well above + AB. Here AB is the delay between the channels, which 100 MS/s are being used in a diverse range of applica- is the combination of the sample clock delay plus the tions from single-pulse linear induction accelerators to difference in analog path lengths of B with respect to A. amplitude and phase measurements on multiple antenna Synchronous sampling is maintained when AB is constant radars. A growing number of such applications require over all i values. By comparison of reconstructed single simultaneous measurement of high frequency signals frequency waveforms from acquisitions on channels A and over many channels. In some of these applications, high B, we can eliminate the sampling clock delay such that AB speed data acquisition is used to capture events in the