HP / Agilent 8444A Tracking generator for 8554B, 8555A

The HP/Agilent 8444A Tracking Generator is a synthesized, frequency-tracking signal source engineered to complement spectrum analyzers including the 8554B and 8555A. It delivers leveled, calibrated RF output across a wide frequency range, enabling swept frequency measurements and direct frequency response characterization of filters, amplifiers, and network components.

Technical Specifications Frequency Coverage

0.5 MHz to 1.3 GHz (standard)

0.5 MHz to 1.5 GHz (with Option 059)

Frequency resolution: 1 kHz Output Characteristics

Continuously variable output level: 0 dBm to −10 dBm

Amplitude accuracy: ±0.5 dB (0.5 to 1300 MHz); ±0.75 dB (0.5 to 1500 MHz)

Tracking generator calibration: 0 dBm ±0.5 dB at 30 MHz

System frequency response: ±2.7 dB

Dynamic range: >90 dB Spectral Purity

Spurious signals: ≥35 dB below output level

Harmonic distortion: 25 dB below output level (typical)

Residual FM noise (peak-to-peak): 200 Hz (stabilized); <10 kHz (unstabilized) Interfaces

Output connector: Type N female

Counter output: 0.1 V rms (typical)

500 MHz third LO output: Available with Option 059 Physical

Weight (with Option 059): 7.1 kg (15.6 lb)

Key Features

Phase-locked synthesis for precise frequency tracking

Leveled output maintains constant amplitude across swept frequency range

Greater than 90 dB dynamic range from 1 dB gain compression to noise floor

Residual FM noise stabilization reduces measurement uncertainty

Typical Applications

Filter and amplifier frequency response measurement

Network component characterization

Swept frequency analysis of RF/microwave circuits

Direct gain/loss measurements on two-port networks

Compatibility & Integration The 8444A integrates with HP/Agilent spectrum analyzers including the 8554B, 8555A, 8590A/B, 8568A/B, and 8558B. When paired with the 8555A, frequency coverage extends to 18 GHz via internal mixer configuration.