Advantest R4131A – 10kHz to 3.5GHz Spectrum Analyzer

The Advantest R4131A is a microcomputer-controlled spectrum analyzer that measures signal magnitude across frequency, enabling detailed spectral analysis from 10 kHz to 3.5 GHz. Built for RF and microwave applications, it delivers precise signal characterization through configurable resolution bandwidth, dynamic range of 80 dB, and maximum input sensitivity of -116 dBm. The instrument provides direct field strength measurements with antenna calibration compensation, quasipeak value detection conforming to CISPR standards, and occupied bandwidth analysis.

Its independent control of center frequency, span, and reference level - coupled with automatic optimization of resolution bandwidth and sweep time - enables efficient operation across diverse measurement scenarios.

Technical Specifications

• Frequency Range: 10 kHz to 3.5 GHz


• Frequency Span: 50 kHz to 4 GHz (configurable)


• Center Frequency Display Resolution: 1 kHz maximum; Accuracy ±10 MHz (R4131C/D) or ±100 kHz (R4131CN/DN) after zero calibration


• Resolution Bandwidth: 1 kHz to 1 MHz (selectable), with automatic setting supported


• Dynamic Range: 80 dB


• Maximum Input Sensitivity: -116 dBm


• Reference Level Units: dBm, dBµV, dBmV, or dBµV/m (selectable with automatic antenna factor correction for field strength)


• Level Data Resolution by Marker: 0.05 dB


• Skirt Characteristics: -80 dBc or better


• Input Impedance: 50 Ω (typical)


• Maximum Input Level: +20 dBm (typical)


• Power Input: 250 V, 6 A


• Weight: 10 kg (22 lbs)

Key Features

• Quasipeak and peak detection modes (POST PEAK, POST/NEG, POSI PEAK displays)


• Non-volatile memory stores three measurement condition sets and three display waveforms


• Waveform storage and recall for comparative analysis


• Auto-recall function restores measurement conditions at power-on


• Independent tuning of center frequency, span, and reference level


• AUTO feature optimizes resolution bandwidth, sweep time, and input attenuator

Typical Applications

• EMI/EMC compliance testing (CISPR standards)


• Signal monitoring and composition analysis


• Occupied bandwidth measurement


• Field strength assessment with antenna-compensated readings

Compatibility & Integration

• 50 Ω RF input; requires horizontal mounting with adequate ventilation


• Standard accessories include input cable (MI-02), fuse, and 3 mm Allen wrench