Advantest R3681 Signal Analyzer

With growing data communications traffic, broadband radio communication systems such as radio-LANs, are being developed that employ various modulation formats. For example, IMT-2000 and other mobile communication systems already use multicarrier methods.

Broadband radio signals are already being used in the RF band. To push this envelope for higher quality data transmissions, researchers and developers are studying higher frequency/broader band carriers.
In this kind of radio communications environment, new measuring instruments are needed that are not only more efficient than ever, but also more flexible to support new test requirements and communication standards.

The R3681 is one of these new measuring instruments for this new era of test and measurement requirements. The R3681 is a high performance signal analyzer. Employing its unique RF technology, the R3681 achieves an Average Display Noise Level of -158 dBm *1), a Third-Order Intercept Point (TOI) specification of +26 dBm *2), and a signal purity of -122 dBc/Hz *3) to enable measurements over a wide dynamic range.
The R3681 also has a unique noise correction function that enhances its dynamic range (-84 dBc [typical]) for W-CDMA adjacent leakage power (ACLP) measurements.

The R3681 supports a standard broadband modulation analysis function (bandwidth 25 MHz). This functionality enables testing of next-generation digital radio communication standards. In short, the R3681 with its W-LAN Signal Analysis Options provides a flexible platform to support next-generation broadband digital radio communications including IEEE802.11a, HiperLAN/2, and HiSWANa.

*1) Typical value at RBW of 1 Hz and 1 GHz with built-in preamplifier off

*2) Typical value at 2 to 3.5 GHz

*3) Typical value at 800 MHz and 10 kHz offset

Features

High-Performance Spectrum Analysis

By making full use of the latest RF techniques, the R3681 enables measurements over a wide dynamic range :

• Average Display Noise Level : -158 dBm (typ. 1 GHz )
• Built-in Preamplifier On : -168 dBm (RBW = 1 Hz, 1 GHz )
• 1 dB Compression Point : +10 dBm (typ. 200 MHz to 3.5 GHz)
• Third-Order Intercept Point (TOI) : +26 dBm (typ. 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 more
• Built-in attenuator with 5 dB steps (standard) : Attenuator with 1 dB steps (OPT.14)
• Resolution Bandwidth (RBW) : 1 Hz to 10 MHz (Sequences 1, 2, 3, and 5)
• Dynamic Range of display :
  10 div. fixed
  0.1 to 1 dB/div. (0.1 dB steps)
  1 to 20 dB/div. (1 dB steps)
• Steep shape factor:
  Approximately 3 times the conventional value.
  This narrows the carrier near-field measurement resolution.

When the noise correction function is on for W-CDMA adjacent channel leakage power ratio (ACLR) measurements, the R3681 achieves :

• -84 dBc
  (typical for one-carrier signal measurements with a 5 MHz offset)
• -77 dBc
  (typical for four-carrier signal measurements with a 5 MHz offset)

W-LAN Modulation Analysis

Broadband measurements with the OFDM modulation analysis function (OPT.68)

• Automatic detection for BPSK, QPSK, 16QAM, or 64QAM
• W-LAN signal analysis with a different modulation for each subcarrier
• W-LAN signal analysis without a preamble
• Signal analysis by the specified number of effective symbols
• I/Q baseband analysis
• Detailed modulation signal analysis using different graphic displays
• Comparative analysis in different display formats using a simultaneous four-screen display
• High operability with a large 12-inch screen and a touch panel