Month: August 2025

Key Features

●Automatically detects BPSK, QPSK, 16QAM, or 64QAM.

WLAN signal analysis with different modulations for each subcarrier

●W-LAN signal analysis without leading codes

●Signal analysis by specified number of valid symbols

●I/Q baseband analysis

●Detailed modulated signal analysis using different graphical displays

Comparative analysis of different display formats using four simultaneous displays

●Enhanced operability with a large 12-inch screen and touch panel

Broadband measurement using OFDM modulation analysis function (OPT.68)

With the addition of Option 68 (Wideband OFDM Modulation Analysis Function), the R3681 can analyse

and measure IEEE802.11a, HiperLAN/2 and HiSWANa modulated signals.

The R3681 can analyse RF inputs, I/Q baseband inputs and wideband WLAN signals.

Extensive Analysis Functions

Equipped with a wealth of standard analysis functions

The R3681 comes standard with the fine measurement functions of ADVANTEST’s conventional spectrum analysers.

The fine measurement functions of a conventional spectrum analyser:

Marker function (multi-marker, triangle marker, peak search, etc.)

Various detection functions required for communication standard measurements Normal value, positive peak, negative peak, sample, RMS value, video average and average voltage.

Other one-touch measurement functions commonly used in RF measurements

Power Measurement Mode

Power measurement (channel power/average power/total power), wideband CCDF measurement, Occupied Bandwidth (OBW) measurement, Adjacent Channel Leakage Power (ACP) measurement, multicarrier measurement, etc.

General Measurement Modes

Spectrum emission mask, spurious measurement, noise/frequency conversion, IM measurement, frequency counter (0.01 Hz resolution), etc.

WLAN modulation analysis

Broadband measurement using OFDM modulation analysis function (OPT.68)

With the addition of Option 68 (Wideband OFDM Modulation Analysis Function), the R3681 can analyse and measure IEEE802.11a, HiperLAN/2 and HiSWANa modulated signals.

The R3681 can analyse RF inputs, I/Q baseband inputs and wideband WLAN signals.

High-performance spectrum analysis

By taking full advantage of the latest RF technology, the R3681 can make measurements over a wide dynamic range.

Measurements are performed over a wide dynamic range:

●Average display noise level: -158 dBm (typical 1 GHz)

●Built-in preamplifier on: -168 dBm (RBW = 1 Hz, 1 GHz)

●1 dB compression point: +10 dBm (typical 200 MHz to 3.5 GHz)

●Third-order intercept (TOI): +26 dBm (typical 2 to 3.5 GHz)

●Signal purity (at 800 MHz)

10 kHz Offset: -120 dBc/Hz or more

1 MHz Offset: -140 dBc/Hz or more

10 MHz Offset: -155 dBc/Hz or higher

Built-in attenuator, 5 dB level (standard)

1 dB level attenuator (OPT.14)

●Resolution bandwidth (RBW): 1 Hz to 10 MHz (Sequences 1. 2. 3. and 5)

Display dynamic range: 10 dB/fixed

0.1 to 1 dB/div. (0.1 dB steps)

1 to 20 dB/div. (1 dB steps)

Steepness shape factor

Approximately 3 times the conventional value. This reduces the resolution of carrier near-field measurements.

■ (AC+DC) AC measurement

The true-RMS measurement of AC allows (AC+DC) measurement

capability for measuring the true effective value of a

distortion wave including the DC components.

■ Internal high capacity data memory

Up to 10000 measurement data can be stored in internal data

memory after operation along with the measurement function

information. This allows measurement for different measurement

functions.

■ Parameter memory function

Up to four measurement conditions can be stored in internal

flash memory as User-0 to User-3, and then any one can be

activated during measurement.

■ Measurement of low power 2WΩ/4WΩ resistance

The low power 2WΩ/4WΩ resistance measurement allows a 1/

10 measurement current setting to minimize the effect of heat

generation during resistance measurement on the component

being tested.

■ Up to seven kinds of operations

Seven kinds of operation (NULL, smoothing, scaling, dB/dBm,

comparator, and MAX/MIN) can be performed on the measurement

data.

■ Optimum remote control capability for system use

The standard GPIB and RS232 interfaces facilitate automated

measurement. Input terminals are available on both the front

and rear panels for easy rack installation.

■ LONG-IT function for averaging of repetitive signals

(DCV, DCI)

The LONG-IT function allows averaging of accurately repetitive

input signals by measuring the same signal twice during

any 10ms interval from 100ms to 60s. This simplifies measurement

of the standby current (average) of PDC/PHS, etc.

■ High performance and high speed sampling

The high performance DMM, with a maximum “319999” (5 1/2

digits) display and ADVANTEST’s unique multiple-slope integral

A/D conversion, is capable of high speed sampling at 1000

samplings/sec in BURST, 100/sec max. in FAST, 20/sec in MED,

and 5/sec max. in SLOW modes. The result of measurement is

stored automatically in internal memory and recalled for later

use. Various operations may be applied to the measured values.

■ Improved AC measurement performance

The AC measurement performance has been further improved

with the measurement ranges of 300mV to 700VAC and 3mA to

3A at basic accuracies of ±0.06% of reading (VAC) and ±0.2%

of reading (AC). The response time is increased 2 to 3 times

while the frequency characteristics are expanded in both the

high and low ranges.

■ Maximum display “319999”

■ High sensitivity DC voltage 0.1μV

Resistance 100μΩ

■ Sampling rate 1000/sec max.

(BURST mode)

■ High accuracy DC voltage ±0.01% of reading (1 year)

AC voltage ±0.06% of reading (1 year)

DC ±0.05% of reading (1 year)

■ Extended integral time can be set (LONG-IT mode) in

10ms steps between 100ms and 60s for averaging

repetitive signals.

■ GPIB and RS232 interfaces (standard) for external

equipment

■ External trigger input, end-of-measurement signal

output (standard)

■ NULL, smoothing, scaling, dB/dBm, comparator, and

MAX/MIN operation capabilities

■ Data memory (1000 data max.)

■ Parameter backup (4 kinds)

■ High speed auto ranging for optimum setting of measurement ranges

■ Fluorescent display tube for enhanced viewing

■ CE marking compliance