HP / Agilent 8449B Microwave Preamplifier, 26.5 GHz

The HP/Agilent 8449B Microwave Preamplifier is a high-gain, low-noise amplifier that extends the sensitivity of RF and microwave measurement systems across the 1 GHz to 26.5 GHz band. By amplifying weak signals before detection, it reduces system noise floor and enables measurement of signals otherwise masked by instrument noise. Minimum gain is 23.5 dB, with typical performance of ≥26 dB across the operating range. The device delivers noise figures of 7 dB typical (1.0–12.7 GHz), 9 dB typical (12.7–22.0 GHz), and 12 dB typical (22.0–26.5 GHz), making it effective for spectrum analyzer applications and low-level signal detection.

Technical Specifications

Frequency Range: 1 GHz to 26.5 GHz

Gain: 23.5 dB minimum; ≥26 dB typical; up to 30 dB

Gain Flatness: ±4.5 dB (1–26.5 GHz, 0–55 °C); ±2.4 dB (2–22 GHz, 20–30 °C)

Noise Figure: 8.5 dB max / 7 dB typical (1.0–12.7 GHz); 12.5 dB max / 9 dB typical (12.7–22.0 GHz); 14.5 dB max / 12 dB typical (22.0–26.5 GHz)

Output Power (1 dB Compression): ≥+7 dBm

Harmonic Distortion: −30 dB at 0 dBm output (characteristic)

Reverse Isolation: >50 dB typical

VSWR Input: 2.0:1 (1.0–2.0 GHz, 12.5–26.5 GHz); 1.5:1 (2.0–12.5 GHz)

VSWR Output: 2.0:1 (1.0–26.5 GHz)

Impedance: 50 Ω

Connectors: Type-N female, ACP 3.5 male

Key Features

Covers full microwave band from 1 GHz to 26.5 GHz with consistent high gain

Low-noise design minimizes degradation of receiver cascade noise figure

Compact half-width package: 214 mm × 133 mm × 366 mm; 7 kg net weight

Optional rackmount kit (Option 908) enables System II integration

50 Ω matched input and output for direct connection to spectrum analyzers

Typical Applications

Extending spectrum analyzer sensitivity for marginal signal detection

Low-level RF and microwave signal measurement

Reducing measurement time in weak-signal environments

Front-end amplification in receiver chains

Compatibility & Integration Designed to interface directly with HP/Agilent spectrum analyzers and RF/microwave test equipment. Type-N and ACP connectors provide compatibility with standard laboratory sources and analyzers.