The HP/Agilent 8405A Vector Voltmeter is a precision RF and microwave measurement instrument designed for simultaneous acquisition of voltage magnitude and phase across dual channels. It characterizes network parameters, amplifier performance, and impedance through direct vector voltage measurement, ratio analysis, and phase difference detection—essential capabilities for circuit design, validation, and production testing.
Technical Specifications
Frequency Coverage
Operates across 1 MHz to 1 GHz in 21 overlapping octave bands with automatic phase-locked tuning to the fundamental frequency within each selected band.
Voltage Measurement
Voltmeter ranges span 100 µV to 1 V rms full scale in 10 dB steps. Channel A ranges vary by frequency: 1.5 mV to 1 V rms (1–10 MHz); 300 µV to 1 V rms (10–500 MHz); 500 µV to 1 V rms (500–1,000 MHz). Dynamic range extends to 10 V rms with the HP 11576A 10:1 Divider.
Phase Measurement
Phase range extends ±180° on a zero-center meter with selectable end-scale ranges of ±180°, ±60°, ±18°, and ±6°. Phase resolution is 0.1° across all angles. Meter offset capability reaches ±180° in 10° increments. Phase accuracy is ±1.5° when Channel A and B voltages are equal.
Voltage Ratio & Gain/Loss
Ratio accuracy: 0.2 dB (1–200 MHz, −60 to 0 dB ranges); 0.5 dB (1–200 MHz, −70 dB and +10 dB ranges); 0.2 dB (200–1,000 MHz, −60 to −10 dB ranges); 0.5 dB (200–1,000 MHz, −70 dB and 0 dB ranges); 1.5 dB (200–1,000 MHz, +10 dB range). Gain or loss measurements exceed 90 dB.
Advanced Measurements
Supports group delay computation for filters and transmission devices, complex impedance characterization, and S-parameter measurement of transistors.
– Key Features
• 1 kHz measurement bandwidth—responds only to signal fundamental frequency
• Channel isolation >100 dB (1–300 MHz); >80 dB (300–1,000 MHz)
• Maximum input: 2 V peak AC; ±50 V DC
• Input impedance: 0.1 MΩ || 2.5 pF (standard); 1 MΩ || 2 pF (with HP 11576A); 0.1 MΩ || 5 pF (with HP 10216A Isolator)
• 20 kHz IF output per channel—reconstructed signals preserving amplitude, waveform, and phase relationships; 1 kΩ series impedance with 2 pF
• Recorder output: 0 to +1 V dc ±6% open circuit, proportional to voltmeter reading
• AC-coupled inputs
– Typical Applications
• Network parameter characterization and impedance analysis
• Amplifier gain and phase response verification
• Filter and transmission device group delay measurement
• Transistor S-parameter extraction
• Signal integrity and ratio measurement in development and manufacturing
– Compatibility & Integration
Optional HP 11576A 10:1 Divider extends measurement range by factor of 10. HP 10216A Isolator available for impedance modification.
