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Oscilloscopes are usually the first instrument of choice when scouring for agile or unknown analog or digital signals. Modern oscilloscopes offer impressive functionality, but operating these scopes can be a challenge. As a welcome contrast, the new R&S RTE digital oscilloscopes from Rohde & Schwarz provide generous measurement capabilities, minus the operating complexity. With each sporting a common-sense operating scheme, efficient internal circuit architecture, and flexible, high-resolution touchscreen, these oscilloscopes are easy to use, even with their many measurement functions. They deliver high resolution and accuracy in two- and four-channel versions with a choice of measurement bandwidths from 200 MHz to 1 GHz. 

The R&S RTE digital oscilloscopes (Fig. 1) are engineered to capture even low-level signals and display results over a wide dynamic range. The different models share a sampling rate of 5 GSamples/s and a fast acquisition rate of more than 1 million waveforms/s. The model lineup is as follows: R&S RTE1022 (two channels, 200-MHz bandwidth); R&S RTE1024 (four channels, 200-MHz bandwidth); R&S RTE1032 (two channels, 350-MHz bandwidth); R&S RTE1034 (four channels, 350-MHz bandwidth); R&S RTE1052 (two channels, 500-MHz bandwidth); R&S RTE1054 (four channels, 500-MHz bandwidth); R&SRTE1102 (two channels, 1-GHz bandwidth); and R&SRTE1104 (four channels, 1-GHz bandwidth).

Versatile Oscilloscopes Capture Signals To 1 GHz, Fig. 1

The 200-MHz models provide better than 1.75-ns risetime, while the 350-MHz instruments achieve risetime of better than 1 ns. The 500-MHz and 1-GHz models offer risetimes of better than 700 and 350 ps, respectively. For frequencies at or less than 500 MHz, the input VSWR is 1.25:1; for frequencies above 500 MHz, the input VSWR is 1.40:1. The oscilloscopes offer input sensitivities of 1 mV/div to 1 V/div input sensitivity at 50 Ω and 1 mV to 10 V/div at 1 MΩ. They capture signals with memory depths ranging from 10 MSamples per channel for four channels (20 MSamples for each of two channels and 40 MSamples for one measurement channel) to as much as 50 MSamples per channel for four channels (100 MSamples for each of two channels and 200 MSamples memory depth for a single measurement channel).

The oscilloscopes are highly accurate with low measurement jitter, with typical timebase accuracy of ±10 ps during a normal calibration interval and ±5 ps timebase accuracy following a calibration. The instruments are beneficiaries of a high-performance, single-core 8-b analog-to-digital converter (ADC) capable of achieving better than seven effective number of bits (ENOB). The single-core data converter is in stark contrast to the typical oscilloscope digitizing architecture in which multiple time-interleaved ADCs are connected to process captured signals, even though errors can arise due to behavioral differences among the different ADCs. The R&S RTE digital oscilloscopes feature a high input sensitivity of 1 mV/div with no compromise on bandwidth or ADC resolution. They waste little time, with less than 300 ns blind time between individual acquisitions.

These flexible, high-performance oscilloscopes employ a unique trigger approach to maintain high accuracy, even when capturing and displaying low-amplitude signals. With this trigger system, one common signal path is used for the acquisition or measurement signal and the trigger signal. By directly analyzing the digitized measurement signal independent of the sampling rate, the oscilloscope can determine if the trigger condition has been met for a signal, even at low amplitudes.

In fact, the oscilloscopes allow flexible adjustment of the digital lowpass filter in the signal acquisition circuitry. The same filter settings can be used for measurement and trigger signals, so that RF noise can be suppressed in support of measuring low-level signals. With built-in fast Fourier transform (FFT) measurement functionality, the spectrum of a waveform can be displayed for analysis in the frequency domain.

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Simplicity Of Operation

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Of course, all this measurement power and capability could be easily lost with a complex operating system. This is where the R&S RTE digital oscilloscopes shine, with each 10.4-in. color touchscreen display serving as a control center and bringer of test results. With the touch of a finger, measurements can be defined, initiated, and completed, and results can be organized and presented on a full-color screen with 1024 × 768 pixel resolution. This fully customizable display even simplifies working with multiple waveform measurements, showing waveforms and measurements along the edge of the screen in the form of signal icons. These icons can be touched, dragged, and dropped onto the main screen at any time for a better view.

The SmartGrid function additionally allows a user to divide the display screen into several “subscreens,” to simultaneously show different waveforms and the results of different measurements. Coupled with the instruments’ “history mode,” which stores previous waveform data, an operator can analyze the background of a signal sequence in search of the source of a signal glitch or problem. A user can essentially operate with the equivalent of several oscilloscopes within this one compact housing, viewing and comparing multiple signals and measurements quickly and easily.

To further simplify measurements, the R&S RTE digital oscilloscopes include a “Quick Meas” function which provides push-button access to some of the more commonly used oscilloscope measurements. These include amplitude, overshoot, duty cycle, frequency, rise time, and fall time, for as many as eight measurements at a time.

Versatile Oscilloscopes Capture Signals To 1 GHz, Fig. 2

In addition, a mask testing function allows users to draw a mask on the touch screen around a desired portion of a waveform, to define waveform and tolerance limits and perform as many as eight measurements at a time according to defined limits. Using just a few keystrokes, an operator can define a mask with as many as 16 segments, or build the mask from a reference signal. Mask segments can be loosely drawn on the display screen and later optimized for greater precision by using the mask test dialog box.

The R&S RTE digital oscilloscopes meld power, precision, and ease of use into packages with a laboratory’s worth of measurement capabilities. In support of the oscilloscopes, the firm offers a variety of options, including a power measurement option, option (B1) for the addition of 16 digital test channels that turns the oscilloscopes into mixed-signal analyzers (Fig. 2), where a logic button provides direct access to the digital channels. The company has developed a broad range of probes to address a variety of applications, usable across all of the firm’s different oscilloscope models.

Rohde & Schwarz USA, Inc., 6821 Benjamin Franklin Dr., Columbia, MD 21046; (410) 910-7800

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