HP 8644A Synthesized Signal Generator is a high performance, 252 kHz to 2060 MHz generator that provides excellent spectral purity for confidence in RF measurements. For R&D or stringent testing of communications equipment, the low phase noise and low spurious provide the measurement margin necessary for repeatability and accuracy.

The HP 8644A is a modular platform that can be configured for specific applications. Performance like spectral purity, frequency range, leakage, and modulation capabilities can all be enhanced with options to the standard instrument to match the signal generator with the application.

For receiver testing or RF design, the HP 8644A provides both low phase noise and low nonharmonic spurious. At 20 kHz offset, 1 GHz carrier, specified phase noise is -128 dBc/Hz standard or -137 dBc/Hz with Option 004. With spurious specified at < -100 dBc, these unwanted signals will not interfere with the measurement results.

For receiver measurements the HP 8644A offers AM, FM, and pulse modulation. FM deviations up to 20 MHz combined with specified rates to 100 kHz can test most communication receivers. AM performance includes 0-100% depth and rates to 100 kHz.

The standard HP 8644A internal source has four modulation tones of 300, 400, 1k, and 3 kHz. Option 007, an optional modulation synthesizer, is available for complex waveforms with frequency coverage from 0.1 Hz to 400 kHz. This source uses digital synthesis to generate waveforms of sine, sawtooth, squarewave, and white Gaussian noise; all with variable frequency, amplitude, and relative phase. The source has the ability to generate four waveforms simultaneously and combine them together with summation and modulation. These complex waveforms are available externally and can be used to extend the frequency range of the HP 8644A down to .1 Hz with complete AM/FM/CW and pulse.

Lowest Specified Leakage of Any Signal Generator

The standard HP 8644A has typical leakage of < 1 µV induced in a two-turn loop, which is sufficient for most R&D or production testing. For sensitive measurements, Option 010, a low leakage configuration, provides more RF shielding and has leakage specified at < 0.05 µV.

On-Site Repair and Calibration

The HP 8644A contains its own firmware for calibration, troubleshooting, and monitoring instrument performance. Built-in sensors continually monitor internal voltages to notify the user of temperature drift, hardware failures, or the need for recalibration. When hardware failures do occur, internal firmware uses these sensors to find a defective module or cable and instruct the operator which hardware to replace. The recommended calibration cycle for the HP 8644A is 3 years.