Vector Signal Generator Cuts Measurement Costs

This powerful bench-top instrument is designed to produce the low-noise, complex waveforms needed to test cellular systems and components through 2200 MHz.

Test sources for modern radiocommunications systems and components must generate complex waveforms. The advent of vector signal generators some years ago solved this problem with wideband internal or external digital in-phase (I) and quadrature (Q) modulation capabilities, although such test sources tend to be expensive. The p1411A RF vector signal generator from precisionWave Corp. ( Colorado Springs, CO), however, packs all the features and performance expected from the most expensive vector signal sources, but at a fraction of the cost. It can operate with its own internal modulation source or with external I and Q signals. It covers the main cellular-band frequencies at 800 to 1000 MHz and 1700 to 2200 MHz.

The p1411A RF vector signal generator (see figure) is an economy test instrument with full-featured performance. It provides the frequency coverage and modulation capabilities needed for cellular-band testing in GSM, EDGE, IS-95 CDMA, NADC, PHS, WCDMA, and various other formats, with 1-Hz tuning resolution and fast tuning speed. The internal modulation source is a 16-b, two-channel, arbitrary waveform generator with 1 MSamples/channel capability. The external modulation inputs support a total modulation bandwidth of 40 MHz.

The p1411A's settling time to within-100 Hz of a new frequency is better than 12 ms from 800 to 1000 MHz and better than 15 ms from 1700 to 2200 MHz. The p1411A commands an output range of 100 to +20 dBm with 0.1-dB resolution. Amplitude is controlled by means of fully electronic attenuation, with settling time of 2.5 ms to within 0.1 dB of a new amplitude setting. The amplitude accuracy is ±0.2 dB following calibration.

A low-phase-noise 10-MHz oven-controlled crystal oscillator (OCXO) is the reference source for the p1411A (the instrument also works with an external 10-MHz reference). It contributes to the low phase noise of −90 dBc/Hz offset 20 kHz from the carrier and −115 dBc/Hz offset 100 kHz from the carrier. Spurious levels are better than −80 dBc across both frequency bands. Harmonics are better than −45 dBc for a +20-dBm output from 800 to 1000 MHz and better than −65 dBc for a +10-dBm output for the same frequency range. For the higher-frequency band, harmonics are better than −35 dBc for a +20-dBm output and better than −50 dBc for a +10-dBm output.

The p1411A provides information on a clear, 7-in. thin-film-transistor (TFT) liquid-crystal-display (LCD) screen that includes a touch panel for ease of control without mouse or keyboard (although these can also be used as input and control devices). The RF vector signal generator occupies three spaces (3U) in a standard 19-in. equipment rack and is 17 in. deep for efficient positioning on a bench top. A unique, patent-pending spectrum-analyzer display provides information about a signal being generated without need of an additional spectrum analyzer. The p1411A is equipped with an Ethernet interface for remote control and access from a local-area network (LAN). P&A: $9900; stock. precisionWave Corp., 7899 Lexington Dr., Colorado Springs, CO 80920; (866) 386-6798, (719) 268-0505, Internet:

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