The Agilent/Keysight 8568B is a benchtop and ATE spectrum analyzer covering 100 Hz to 1500 MHz with exceptional frequency stability and sensitivity. It delivers noise floors as low as −135 dBm using a 10 Hz resolution bandwidth, enabling precise measurement of small signals amid interference. The instrument combines narrow-bandwidth crystal filters, wide dynamic range (−135 dBm to +30 dBm), and temperature-stable frequency reference accuracy of better than 7 × 10⁻⁹ across 0° to 55 °C.
Technical Specifications
Frequency & Resolution
• Frequency range: 100 Hz to 1500 MHz
• Resolution bandwidth (crystal filters): 10 Hz, 30 Hz, 100 Hz, 300 Hz, 1 kHz
• Sweep time (full span): 20 msec to 1500 sec
• Sweep time (zero span): 1 µsec to 1500 sec
Sensitivity & Amplitude
• Measurement range: −135 dBm to +30 dBm
• Noise floor: −135 dBm (10 Hz RBW); −129 dBm at RF Input #1 above 1 MHz (10 Hz RBW)
• Amplitude accuracy: ±1.0 dB across full frequency range
• Readout accuracy: Center frequency accuracy + ½ frequency span accuracy
Frequency Stability
• Temperature stability: <7 × 10⁻⁹ over 0° to 55 °C
• Frequency reference accuracy: <7 × 10⁻⁹ over 0° to 55 °C
• Frequency span accuracy: ±(2% of span + reference accuracy × tune frequency + 10 Hz) after zero-frequency adjustment at stabilized temperature
Display & Memory
• CRT monochrome display with 10-division horizontal axis
• User RAM: 16 KB for trace data, instrument states, and downloadable programs
• Non-volatile memory for analyzer control settings
Inputs & Interfaces
• RF Input #1: 100 Hz to 1500 MHz, DC coupled (BNC, 75 Ω, unfused)
• RF Input #2: 100 kHz to 1500 MHz, AC coupled
• External tracking generator (not included)
Operating Environment
• Temperature range: 0° to 55 °C
• Power: External AC source required
– Key Features
• Multiple trace display for residual FM and drift measurement
• Real-time signal surveillance across wide frequency range
• Downloadable programs executable via custom softkeys
• Stored analyzer configurations recalled from non-volatile memory
– Typical Applications
• Benchtop RF signal measurement and analysis
• Automatic test equipment integration
• Small signal detection in high-interference environments
• Signal stability and spectral purity assessment
– Compatibility & Integration
The 85685A RF preselector can be added to enhance high-performance spectrum analysis and convert the 8568B into a specialized test receiver.
