N6841A RF Sensor for Signal Monitoring Networks

N6841A RF Sensor for Signal Monitoring Networks

Data Sheets

The N6841A RF sensor offers a distributed and autonomous concept in spectrum monitoring. Communication signals have evolved dramatically and continue to do so as new and emerging wireless standards are defined and deployed. The new generation signals are wider bandwidth, more complex, time-variant, and low power.

Traditional methods of monitoring communication signals from outside the city limits, in a crowded vehicle, or walking with a handheld analyzer don’t work well on these new standards or today’s interference problems.

The N6841A RF sensor offers a cost-effective solution to placing a fully capable RF monitoring station where you need it when you need it for as long as you need it, without complex siting constraints or physical infrastructure.

Key features

  • Environmentally rugged IP67-rated weatherproof enclosure. Sealed unit with no moving internal parts
  • Small footprint for easy setup and teardown – ideal for fixed or temporary installations
  • Wideband RF receiver with 20 MHz to 6 GHz frequency tuning range
  • Digital IF bandwidth up to 20 MHz
  • Signal LOOKback and capture memory (4.8 secs at 20 MHz BW) enables reliable detection, processing, and location of short duration signals or interference
  • I/Q streaming up to 2 MSa/sec for recording and off board signal processing
  • Integrated GPS for sensor location and time synchronous applications
  • High precision measurement synchronization and timestamping
  • AM/FM demodulated audio streaming
  • Two type-N RF input ports (switched) for multiple antennas
  • Well documented API for user programming and application development
  • Wide range of sensor applications to meet your specific monitoring, analysis, or location requirements
  • Embedded Application support for autonomous spectrum monitoring

RF sensor use models

  • Spectrum survey with signal classification and database operations
  • Interference detection, collection, classification, identification, and location
  • Band Clearing/spectrum occupancy/utilization monitoring
  • Border or regional area RF monitoring and emitter geolocation
  • Range monitoring
  • Spectrum awareness associated with RF testing
  • Enforcing your organization or facility spectrum policy

RF sensor users

  • Frequency regulatory agencies
  • Mobile service providers
  • Government range managers
  • Spectrum/frequency managers
  • RF test managers
  • Military and Intelligence operations
  • Anyone monitoring or working with “off the air” RF signals

Deployment

The N6841A RF sensor has a weatherproof and dustproof IP67-rated (Standard IEC 60529 International Protection 67) enclosure with a wide operating temperature range to withstand harsh environments. The conductively cooled unit is silent and contains no moving parts and operates over a temperature range of –15 °C to 55 °C. You can extend the operating temperature range by using a commercially available enclosure that includes heat and ventilation for extreme temperature conditions.

The N6841A RF sensor has a small footprint with no external switches or status indicators making it extremely discreet. The low-profile form factor offers many mounting options, including tripod, roof-top, pole-top, rackmount, vehicle-mount, or man-pack deployments. Relative to other solutions, the N6841A RF sensor requires minimal installation effort and is likely to gain easy mounting approval from building managers. It is also very well suited to temporary installations.

On-board diagnostics include a complete self-test of the internal RF signal path and a watchdog reset timer which reduces the need for on-site troubleshooting. Installation and configuration of the RF sensor is simple with only RF input, GPS antenna (optional), power, and network connections.

RF sensor antennas

You can use the N6841A RF sensor with any passive or active antenna element. For maximum flexibility of the solution, the RF sensor does not require a specific antenna. However, the Keysight N6850A antenna provides excellent broadband omnidirectional characteristics and good coverage, without excessive expense or additional power.

RF sensor power considerations

Power the N6841A RF sensor with 15 to 24 volts DC and expect to draw less than 30W. The N6841A-SP1 provides a 120/240 VAC power supply suitable for indoor (protected) installations. Off-the-shelf batteries are available from several suppliers that can power the RF sensor for up to eight hours. There are also power supplies rated for outdoor use available commercially. The RF Sensor ships with an extra power connector for use with an alternate power source.

Network connections

Often, a wired Internet connection is not possible for the ideal RF sensor locations. In these cases, either a cellular modem, mesh radio network, or Wi-Fi backhaul may be an option. Standard Wi-Fi radios with directional antennas can easily service the data connection to an RF sensor over several km. If you need greater distances, a cellular modem provides the freedom to site the sensor anywhere in the cellular coverage area. If wired Ethernet is available for your installation, a shielded cable is highly recommended

Physical mounting

The N6841A RF sensor ships with a complete mounting kit for attachment to a rack, wall, rail, or pole. The mounting bracket includes provision for security locks, attachment of the GPS antenna, and the RF sensor. Aside from the RF antenna, the N6841A requires only one mechanical connection to the pole for a new RF monitoring station.

Multiple sensors

A benefit of deploying multiple sensors is improved RF detection range and the ability to make time synchronous I/Q and spectral measurements. This capability opens the door to emitter location, direction-finding, propagation studies, and other time-correlated applications. You can synchronize N6841A RF sensors using two different methods: GPS (for outside deployments) and IEEE-1588 (for indoor deployments or wherever GPS is unavailable or unreliable.