Agilent / Keysight 8683B Signal Generator

The Agilent/Keysight 8683B is a portable signal generator engineered for benchtop and field maintenance environments. It delivers signal generation across the 2.3 GHz to 6.5 GHz band with comprehensive modulation support including AM, FM, and pulse modulation. This instrument is well-suited for testing communications, radar, and electronic warfare systems.

Though obsolete and no longer manufactured by Keysight, technical support remains available.

Technical Specifications

• Frequency range: 2.3 GHz to 6.5 GHz


• Frequency resolution: 5 MHz


• Output power: +10 dBm to -130 dBm (leveled into 50 Ω)


• Level accuracy: ±2.5 dB from maximum to -110 dBm; +3.5 dB to -120 dBm


• Typical level accuracy at -100 dBm: -10 dBm): +1.0 dB


• Harmonics (<18 GHz, 10 dBm): <25 dBc Modulation


• AM depth: 0 to 70% (1 kHz)


• AM distortion (THD): <10% at 40% depth, 1 kHz rate


• Incidental AM: <6% (rate <100 kHz, peak deviation <1 MHz)


• FM deviation: ±5 MHz (main band)


• FM rates (3 dB BW): DC to 10 MHz (DC coupled); 100 Hz to 10 MHz (AC coupled)


• FM distortion: <5% at 100 kHz rate, <1 MHz peak deviation


• Incidental FM: 100 ns


• RF pulse rise/fall time: 80 dB


• Maximum pulse repetition frequency: >1 MHz Phase Noise


• Single-sideband phase noise (10 kHz offset): <-72 dBc/Hz (8683B) Physical and Operational


• Dimensions: 145 mm H × 457 mm W × 472 mm D


• Weight: 17.9 kg (net); 23.4 kg (shipping)


• Display: 4-digit LED


• Frequency switching speed: <20 μs (typical)

Key Features

• Internal pulse generator with 7 adjustable width ranges


• Dual modulation input capability (internal and external AM, FM, pulse)


• Phase lock input with -5 MHz/V typical sensitivity


• 4-digit LED display for parameter readout


• Option 003 for 400 Hz line operation

Typical Applications

• Communications system testing


• Radar and countermeasure validation


• Electronic warfare receiver evaluation


• Field maintenance and troubleshooting

Compatibility & Integration External modulation inputs accept AM, FM, and pulse signals. Phase lock capability allows synchronization with external frequency references. Dual-band configurations available through Option 001.