Electronic Design

Real-Time Spectrum Analyzer Handles 36-MHz Bandwidth

RF signals aren't just becoming more prevalent in consumer and industrial designs, they're also becoming more complex and transient. Frequency hopping, bursting, and modulation can help systems avoid interference, maximize peak power, and avoid detection. But everything comes at a price. These signals create problems that are difficult to troubleshoot.

The RSA3408A real-time spectrum analyzer from Tektronix targets those problems. Unlike swept-spectrum analyzers, which typically provide a one-dimensional "snapshot" of the signal, the RSA3408A captures and records all the signals across a user-selected bandwidth of up to 36 MHz. In one acquisition, the instrument can simultaneously measure pulse width, pulse-to-pulse phase, pulse ripple, carrier frequency, emissions bandwidth, and many other factors (see the figure). It also can measure individual pulses and display them as trends across all pulses in an acquisition.

Power and frequency triggers enhance flexibility. A power trigger captures a spectrum whenever the total power of all signals in an analysis span crosses a user-defined threshold. A patented frequency mask trigger (FMT) option captures the spectrum of interest when a discrete change in signal frequency, amplitude, or bandwidth occurs.

Triggering occurs even if spectral events are detected at a much lower level than adjacent signals. The FMT also lets users create customized masks to monitor multiple frequency bands with the analysis span. To capture infrequent events, a continuous trigger mode constantly monitors the selected spectrum and makes an acquisition only when user-defined criteria are met.

The RSA3408A uses a 102.4-Msample/s, 14-bit analog-to-digital converter. Its frequency range is 8 GHz. Third-order intermodulation distortion is ­78 dBc and displayed average noise level is ­151 dBm at a 1-GHz center frequency. Prices start at $49,800.

Tektronix Inc.

TAGS: Components
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