The Keysight/Agilent/HP 8657A is a synthesized signal generator delivering precision RF signal generation from 100 kHz to 1.04 GHz with 10 Hz resolution. Built for wireless communications, radar testing, and component characterization, this instrument combines broad frequency coverage with flexible modulation capabilities and exceptional spectral purity.
– Technical Specifications
Frequency Performance
• Range: 100 kHz to 1.04 GHz
• Resolution: 10 Hz
• Switching Speed: <35 ms
• Low Residual FM: <4 Hz typical (<2 Hz) in CW mode (rms)
Amplitude Control
• Output Range: +13 dBm to −143.5 dBm (50 Ω)
• Resolution: 0.1 dBm
• Absolute Level Accuracy: ±1.0 dB (typically ±0.5 dB)
• Level Flatness: ≤1.0 dB (100 kHz to 990 MHz at 0 dBm)
• SWR: −5 dBm); <1.5 (<−5 dBm)
• Reverse Power Protection: Up to 50 W; 25 W to 990 MHz
Modulation Capabilities
• Modes: AM, FM, Phase Modulation (ΦM), Pulse Modulation (optional)
• AM/FM simultaneous operation supported
• DC-coupled FM for VCO simulation and long-term stability
• AM Distortion: <1.5% (0–30% depth); <3.0% (31–70% depth)
• FM Distortion: <1.5% harmonic and non-harmonic (DC to 100 kHz external rates)
Spectral Purity
• SSB Phase Noise: −136 dBc/Hz at 20 kHz offset
• Harmonics: <−30 dBc
Phase Control
• Adjustable output signal phase in 1-degree nominal increments
• Enables characterization of phase-sensitive devices
– Key Features
• All-electronic attenuator for measurement reliability
• Low RF leakage minimizes test interference
• Non-volatile memory stores up to 100 front-panel setups
• HP-IB remote programming interface
• Optional high-stability timebase, GMSK modulation (0.3 or 0.5), and pulse modulation to 1040 MHz
– Physical Specifications
• Dimensions: 133H × 425W × 520D mm
• Net Weight: 18.1 kg; Shipping Weight: 23.6 kg
– Typical Applications
Wireless communications testing, radar system characterization, RF component evaluation, VCO simulation, phase-sensitive device measurement.


















