Agilent Technologies 89600 manual

In addition to the time record length limits, there are limits to the allowable range of spans. These are represented as vertical lines on the operating region graphs (Figure 4). The upper span limit is set by the digitizer’s sample rate. For the highest sample rate supported by the digitizer this boundary may be further limited by the analog performance of the digitizer’s front-end. To zoom in on a signal of interest by reducing the span, traditional VSA instrumentation reduces the effective sample rate through the use of decimating filters while keeping the ADC at full rate. This technique allows for maximum alias protection. Unlike traditional VSA instruments, the Acqiris digitizers have no decimating filters.

To compensate for this shortcoming, decimating filters have been built into the 89600 VSA software. The maximum amount of decimation allowed by the 89600 VSA software sets the minimum span for any given digitizer sample rate.

The operating region depicted in Figure 4 is determined by constraints imposed by both time record length and span. The Acqiris digitizers support many sample rates. For each sample rate, the operating region shifts slightly on the operating region graph. As the sample rate decreases, the operating region shifts slightly up and to the left. So, for any given digitizer, there will be a family of overlapping operating regions, one for each supported sample rate.

In general, these regions would be the same for every digitizer that supports a given sample rate. The only difference is when the maximum span at the maxi- mum sample rate is limited by analog performance of the digitizer’s front-end rather than just by the sample rate.

In addition to the time record length limits, there are limits to the allowable range of spans. These are represented as vertical lines on the operating region graphs (Figure 4). The upper span limit is set by the digitizer’s sample rate. For the highest sample rate supported by the digitizer this boundary may be further limited by the analog performance of the digitizer’s front-end. To zoom in on a signal of interest by reducing the span, traditional VSA instrumentation reduces the effective sample rate through the use of decimating filters while keeping the ADC at full rate. This technique allows for maximum alias protection. Unlike traditional VSA instruments, the Acqiris digitizers have no decimating filters.

To compensate for this shortcoming, decimating filters have been built into the 89600 VSA software. The maximum amount of decimation allowed by the 89600 VSA software sets the minimum span for any given digitizer sample rate.

The operating region depicted in Figure 4 is determined by constraints imposed by both time record length and span. The Acqiris digitizers support many sample rates. For each sample rate, the operating region shifts slightly on the operating region graph. As the sample rate decreases, the operating region shifts slightly up and to the left. So, for any given digitizer, there will be a family of overlapping operating regions, one for each supported sample rate.

Taken altogether, these constraints form an operating region that the 89600 VSA software must remain within (Figure 6). To complete our understanding there are a couple of additional points regarding sampling mode and alias exposure that must be presented.

The graphs presented in this section describe discrete operating regions that are a function of sample rate. In full rate or user rate sample modes a single operat- ing region curve fully describes the constraints imposed on the measurement.

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