Agilent / Keysight 8645A Frequency-Agile Signal Generator, 1 GHz or 2 GHz

The Agilent/Keysight 8645A is a frequency-agile signal generator delivering precise RF signal generation from 252 kHz to 1030 MHz (extendable to 2060 MHz with Option 002 or HP 11845A retrofit). It combines static and dynamic signal synthesis capabilities for testing frequency-hopping radios, surveillance receivers, and agile communication systems.

Technical Specifications

• Range: 252 kHz to 1030 MHz; up to 2060 MHz with Option 002 or HP 11845A retrofit kit


• Accuracy: ±2 ppm of carrier frequency


• Fast hop switching: <15 µsec (128 MHz to 2060 MHz), <85 µsec (8 MHz to 2060 MHz), <500 µsec (0.25 MHz to 2060 MHz); add 5 µsec with Option 002


• Hop range: 0.25 to 2060 MHz; limited to three consecutive frequency bands when FM is active


• Fast hop sweep: Linear or log stepped, 10 ms to 100 s


• Phase continuous sweep: Linear, 10 ms to 10 s Amplitude


• Maximum output: +16 dBm (0.25–1030 MHz), +13 dBm (1030–2060 MHz); +14 dBm at 0.25–1030 MHz with Option 002


• Minimum output: −137 dBm


• Resolution: 0.1 dB


• Accuracy: ±1 dB (≥−127 dBm), typically ±3 dB (<−127 dBm); ±1.5 dB during fast hop with amplitude variation up to −5 dB


• Output impedance: 50Ω; SWR <1.7:1 (output <−2 dBm), <2:1 (≥−2 dBm)


• Reverse power protection: 50 W from 50Ω source, 25 Vdc


• Switching time: <50 msec Modulation


• Types: AM, FM, simultaneous FM/AM, pulse


• FM: Deviations to 20 MHz, rates to 10 MHz; fast hop limited to 3.5 MHz deviation at 10 MHz rates; distortion <1–6%; residual FM <1–4 Hz


• AM: Depth 0–99.9% (output ≤+7 dBm); indicator accuracy ±(6% of setting + 1% AM) to 90% depth at 1 kHz


• Internal modulation: Sine, square, sawtooth, white Gaussian noise; 0.1 Hz–400 kHz (sine/noise), 0.1 Hz–50 kHz (square/sawtooth); ~1 V max into 600Ω

Key Features

• Sub-microsecond frequency hopping for agile signal simulation


• ±2 ppm frequency stability across extended range


• Wide dynamic range: −137 to +16 dBm with 0.1 dB resolution


• Simultaneous FM/AM modulation with low residual FM


• Pulse modulation support for radar and communication testing

Typical Applications

• Frequency-hopping radio receiver validation


• Surveillance and electronic warfare receiver testing


• Communication system dynamic signal simulation


• Fast-switching RF transceiver characterization

Compatibility & Integration Option 002 extends frequency coverage to 2 GHz and improves switching performance. The HP 11845A 2 GHz retrofit kIt has equivalent high-frequency capability. Both options are field-installable.