The USB-5681 from National Instruments is a USB true RMS power meter that operates from 10 MHz to 18 GHz. It has a dynamic range from -40 to +20 dBm and a linearity of under ±0.18 dB. The device draws only 150 mA from the USB connection, making it highly suitable for mobile applications or adding to automated test applications to free up valuable rack space.

You can hardware-trigger the USB-5681 through an external trigger source or software-trigger it based on the signal source. Scope and slot modes use this software triggering to measure burst waveforms, such as WiMAX and LTE, and multislot waveforms, such as GSM and EDGE. The power meter is self-contained in a small form factor with calibration constants, including linearity and temperature corrections stored directly on the device.

Product Specifications

Product Details

  • Part Number
    NI USB-5681
  • Manufacturer
    National Instruments Corporation
  • Description
    USB True RMS Power Meter from 10 MHz to 18 GHz

General Parameters

  • Type
    Power Meter, Power Sensor
  • Configuration
    Computer Controlled
  • Power Measurements
    Average/CW
  • Frequency
    10 MHz to 18 GHz
  • Channels
    Single Channel
  • Power Range
    -40 to 20 dBm
  • Impedance
    100 kO
  • Interface
    USB
  • Measurement Resolution
    0.01 dB
  • Return Loss
    19 to 22 dB

Technical Documents