Agilent / Keysight 8656A Synthesized Signal Generator, 0.1 to 990 MHz

The Agilent/Keysight 8656A is a synthesized signal generator delivering programmable RF signal generation from 0.1 MHz to 990 MHz with 10 Hz frequency resolution. This instrument combines precise amplitude control (0.1 dB resolution, +13 dBm to -127 dBm output range) with integrated modulation capabilities, supporting both AM and FM modes simultaneously or independently. Frequency switching completes in less than 35 ms to within 100 Hz of the carrier frequency, enabling rapid frequency-agile testing protocols. The architecture maintains level flatness of ≤1.0 dB across the operating frequency range at 0 dBm output, with absolute accuracy of ±1.0 dB in the 123.5 MHz to 990 MHz band. AM modulation reaches 99% depth with <1.5% distortion at frequencies ≥400 kHz and output levels ≤+7 dBm. FM capabilities span internal rates at 400 Hz and 1 kHz, plus external rates DC to 100 kHz, with harmonic and non-harmonic distortion 0.15 V into 50 Ω) selectable to 1, 5, or 10 MHz. Compact benchtop form factor (425 mm × 520 mm × 133 mm, 18.1 kg) accommodates lab and field deployment across operating temperatures 0°C to 55°C. Standard power requirements accept 100, 120, 220, or 240 Vrms (±5%, -10%) at 48–440 Hz with maximum consumption of 125 VA.