1. General Performance & Leveling

️· Resolution: 0.01 dB
️· Temperature Stability: 0.02 dB/°C (typical, varies by option).
️· Level Accuracy: Generally ± 1.0 to ± 1.9 dB, dependent on frequency, mode and optional features.
️· Leveling Modes: Internal, external detector, millimeter source module, ALC off.
️· External Detector Leveling: Range -0.2mV to -0.5V, selectable bandwidth.
️· Adjustable RF Output Limit: User-adjustable, protects external devices.

2. Frequency & Amplitude Switching

️· Amplitude Switching Speed (ALC On): < 6 ms (typical)
️· Amplitude Switching Speed (ALC Off): < 10 ms (typical, not including power search)
️· Level Accuracy (10MHz to 60MHz): Nominal above +16 dBm

3. SWR (Standing Wave Ratio)

️· 250 kHz to 2 GHz: < 1.4:1 (typical) - varies with options.
️· 0.5 to 20 GHz: < 1.8:1 (typical)
️· 20 to 40 GHz: < 1.6:1 (typical)
️· 40 to 67 GHz: < 2.0:1 (typical)
️· *Note: SWR is highly dependent on option configuration.*

4. Harmonic Performance

️· With Option 1EH filters off: -8 dBc (typical)
️· With Option 3EH filters on: -55 dBc (typical)
️· *Harmonic specifications are heavily tied to the 1EH low-pass filter option.*

5. Output Impedance & Reverse Power

️· Output Impedance: 50 Ω (nominal)
️· Maximum Reverse Power: Varies depending on frequency and option. Up to 2 watts below 250 MHz, 1/2 watt above 250MHz for units without Option 1E1.

6. User Flatness Correction (Important for Calibration/Accuracy)

️· Points: 2 to 1601 points/table
️· Tables: Up to 10,000 (memory limited)
️· Entry Modes: Remote power meter, remote bus, manual.

7. Option Specific Features

️· Option 521: Includes low-pass filters below 2 GHz as standard. Better SWR.
️· Option 550/567: Temperature stability degrades above 2 GHz.
️· Option 1EH: Critical for harmonic performance.
️· Option 1E1: Affects SWR and reverse power handling.

IMPORTANT NOTES & DISCLAIMERS:

️· Partial Document: This is a *summary* extracted from a specific section of the Keysight E8257D datasheet. It does *not* contain all specifications or operating information. Consult the full datasheet for complete details.
️· Option Dependent: Many specifications are heavily dependent on the specific options configured on the instrument. "Typical" values are not guaranteed and may vary significantly.
️· Environmental Conditions: Specifications are generally valid under specified temperature and humidity conditions.
️· Load Conditions: Most specifications assume a 50-ohm load. Performance will vary with different load impedances.
️· Measurement Procedures: Specifications are based on defined measurement procedures, which may not be identical to how a user would perform a measurement in a specific application.