Agilent / Keysight 8648D Synthesized RF Signal Generator, 9 kHz to 4000 MHz

The Agilent/Keysight 8648D is a synthesized RF signal generator covering 9 kHz to 4000 MHz with calibrated output power, precise frequency control, and versatile modulation capabilities. Designed for high-volume manufacturing, semi-automated receiver testing, and general-purpose signal sourcing, the 8648D delivers measurement consistency and repeatability across diverse test environments.

Technical Specifications

• Operating range: 9 kHz to 4000 MHz


• Settable resolution: 0.001 Hz increments


• Display resolution: 10 Hz


• Frequency accuracy (standard): ±3 × 10⁻⁶ × carrier frequency


• Frequency accuracy (Option 1E5 High Stability): ±0.15 × 10⁻⁶ × carrier frequency


• Aging rate (standard): <±2 ppm/year


• Aging rate (Option 1E5): <±0.1 ppm/year


• Temperature stability (standard): <±1 ppm


• Temperature stability (Option 1E5): <±0.01 ppm


• Frequency switching: <75 ms below 1001 MHz; <100 ms at 1001 MHz and above Output Power


• Range below 2500 MHz: +13 dBm to -136 dBm


• Range below 4000 MHz: +10 dBm to -136 dBm


• Output impedance: 50 ohms nominally


• Reverse power protection: 50 watts (≤2000 MHz); 25 watts (≤4000 MHz)


• Power accuracy below 2500 MHz: ±1.0 dB


• Power accuracy below 3200 MHz: ±1.5 dB


• Power accuracy below 4000 MHz: ±2.0 dB Spectral Purity


• Harmonics (≤+4 dBm output): <-30 dBc


• Subharmonics below 1001 MHz: <-60 dBc


• SSB phase noise at 500 MHz (20 kHz offset): <-120 dBc/Hz


• SSB phase noise at 1000 MHz (20 kHz offset): <-116 dBc/Hz


• SSB phase noise at 2000 MHz (20 kHz offset): <-110 dBc/Hz Output Characteristics


• SWR below 2500 MHz (output <-6 dBm): <1.5:1


• SWR below 4000 MHz (output <-6 dBm): <2.0:1

Key Features

• High-precision frequency synthesis with 0.001 Hz tuning resolution


• Optional 1E5 timebase reduces aging to ±0.1 ppm/year and improves temperature stability to ±0.01 ppm


• Wide dynamic range from +13 dBm to -136 dBm below 2500 MHz


• Fast frequency switching supports rapid test sequencing


• Clean spectral output with suppressed harmonics and subharmonics

Typical Applications

• High-volume receiver manufacturing and characterization


• Semi-automated test systems requiring repeatable signal generation


• Filter and amplifier validation across UHF and microwave bands


• Production test environments demanding consistent phase noise and spectral purity

Compatibility & Integration The 8648D operates with 50-ohm RF systems. Output protection to 50 watts (≤2000 MHz) and 25 watts (≤4000 MHz) safeguards against reflected power. Option 1EA High Power extends maximum leveled output to +20 dBm at 1000 MHz for demanding test scenarios.