The Advantest U4941 is a portable RF field analyzer designed for field strength measurements and EMI analysis from 9 kHz to 2.2 GHz. This lightweight instrument combines wide frequency coverage with selectable resolution bandwidths ranging from 1 kHz to 3 MHz, enabling precise signal characterization in both laboratory and field environments.
Technical Specifications
Frequency & Resolution
• Frequency range: 9 kHz to 2.2 GHz
• Resolution bandwidth: 1 kHz to 3 MHz (selectable)
• Display dynamic range: 100 dB
• Input impedance: 50 Ω nominal (U4941/U4941N); 75 Ω nominal (U4941N variant)
Signal Integrity
• VSWR (preamplifier OFF): ≤1.5:1 from 100 kHz to 2 GHz; ≤2:1 from 9 kHz to 2.2 GHz
• VSWR (preamplifier ON, 10 MHz to 2.0 GHz): <2:1
• Internal preamplifier gain: 20 dB
• Single-sideband noise floor: -105 dBc/Hz to -100 dBc/Hz
• IF gain uncertainty (post-calibration): <+0.5 dB
• Scale fidelity (post-calibration): +1.5 dB/90 dB logarithmic; <+1 dB/10 dB; <+0.2 dB/1 dB
Power & Portability
• AC mains, external DC (+10 to +16 V), or optional battery pack (≈2 hours operation; 1-hour rapid charge)
• Weight: 6.5 kg
• Dimensions: 5.8 × 11.5 × 13 inches
– Key Features
• Built-in quasi-peak detector and EMC filters for EMI/RFI measurements
• Reduced dB measurement function
• N-type RF input connector
• Video output (BNC, 75 Ω, 1 Vp-p); phone output (0.2 W into 8 Ω)
• External trigger (BNC) and gate inputs (10 kΩ nominal impedance)
• Two PCMCIA slots for data storage and instrument configuration recall
– Interfaces & Control
• IEEE-488 bus connector for spectrum analyzer integration
• RS-232 serial interface (D-SUB 9-pin)
• TTL-compatible external trigger input
– Typical Applications
Field strength surveys, broadband EMI/RFI characterization, on-site maintenance diagnostics, and frequency spectrum assessments in telecommunications, broadcast, and industrial RF environments.
