N6820NBRE Narrowband Receiver (NBR) Feature

Introduction

Keysight’s N6820NBRE is a licensed software feature that enables Surveyor 4D software to stream both spectrum and time-series IQ data from capable receivers to the host PC for gap-free recording with live real-time spectrum updates. The receivers capable of streaming include the N6831A VLF-HF wideband receiver and the N6841A RF Sensor. Operation of NBR requires a solid physical network connection between the host PC and the receiver to achieve full throughput. NBR takes advantage of one or more digital downconverters (DDCs) enabled in the receiver.

• The N6831A receiver has up to 128 DDCs with recording bandwidths of up to 800 kHz

• The N6841A receiver has two modes that can use the NBR feature:

  o Single DDC with recording bandwidth up to 1.5625 MHz (2 MSa/sec sample rate)

  o Multi-DDC with up to 8 DDCs with recording bandwidths up to 156.25 kHz

NBR setup

The N6820NBRE software feature setup enables users to specify center frequency, sample rate, time offset (for delay or pre-trigger recording), maximum duration, threshold level, and dwell time. The threshold level is used in conjunction with the dwell time to trigger a recording and continues until the signal has dropped for a time length that exceeds the dwell time. Setup can be either manual, using the assigned menu in the NBR signal processing window, or automatic, using the NBR alarm task.

Recordings are raw IQ time-series data in the Keysight file format *.cap. The CAP file is fully documented in the E3238s Command Reference. The files are compatible with: 

• Keysight 89601C200 Vector Signal Analyzer software

• N6820MR1E Modulation recognition feature

• N6820VRXE Virtual receiver platform

• N6829BS Snapshot radio software

Key features

• Gap-free streaming narrowband recording

• Raw IQ time-series file format is compatible with a variety of analysis software

• Real time spectral display while recording

• Manual or automated operation

N6820NBRE Installation

The N6820NBRE feature is included with the base N6820ES S4D download found at www.keysight.com/find/N6820ES. There is no special installation needed, however, the feature is enabled with a license file.

After installation, you will find new folders that contain pre-configured applications to use the NBR feature with either the N6831A or N6841A receiver:

• The Apps folder found at C:/E3238s/Apps/RFSensor/NBR includes a shortcut to a standard NBR configuration using the N6841A RF sensor. The setup includes a frequency list labeled “Auto Record”. When frequencies are added to the list, they are automatically recorded for 30 seconds when energy is detected.

• The Apps folder found at C:/E3238s/Apps/VRT/NBR includes a shortcut to a standard NBR configuration using the N6831A VLF-HF receiver.

Application Software licensing options

Flexible licensing options allow you to balance your project’s requirements. Your application software may require consistent software operation over a full program lifecycle or may require frequent updates to maintain pace with fast-moving leading-edge applications. Keysight licensing has flexible license terms and types to address your application needs. KeysightCare provides selectable software support as well.