Spectrum Monitor
Low cost portable spectrum monitor, providing a quick and reliable reading of ambient RF-Signal Levels in internationally assigned radio communications bands. Deployment may be covert or overt.
Overview
Developed by Crownhill Associates Limited this low cost solution provides reliable detection of RF sources. A spectrum analyser remains the instrument of choice for detecting and identifying RF activity. However Spectrum Analysers are expensive bulky and not always readily available. This solution provides RF detection in specific frequency bands using state of the art technology in a small and flexible form factor. Presented as a dedicated product or an OEM module for use in thrid party solutions.
Output from the monitor can be used to trigger local alarms, remote alarms via ethernet or covert personal alerting via vibration.
Spectrum Monitor is a proven design aaimed at bespoke applications tailored to end user requirments.
Methodology
Based upon a highly selective front end tailored to the band or bands of choice, the Spectrum Monitor utilises multisatge logarithmic amplifiers to accurately convert radio frequency signals power to an equivalent DC voltage. Full advantage is taken of multi layer chip band pass filters, to provide high attenuation of unwanted signals. The outstanding dynamic range and precision over temperature make the design particularly suitable for harsh environments and situations where false alarms are extreemly undesirable.
Potential uses
The sspectrum monitor is incredibly versatile. Potentially examples of deployment include:
Deterrent
- Hospitals
- Theatres and Cinemas
- Airports
- Military Bases
- High-security areas
- Examinations (Schools, Universities, etc)
Covert
- Prisons and Correctional facilities
- Surveillance operations
- Mobile Phone detection
- Off Air IMSI/TIMSI monitoring
- Passive GSM Intercept
General Specifications
- Operation in bands from 50Mhz to 7Ghz with extention to 10Ghz
- upto 120db dynamic range (60db for near feild applications)
- Detector output via dry contact, DC level, opto, ethernet, audio
- Low power consumption
- small footprint
Typical Band coverage
GSM 850 Band:
- 824 MHz to 849 MHz: mobile transmit, base receive;
- 869 MHz to 894 MHz: base transmit, mobile receive.
Standard or primary GSM 900 Band, P‑GSM:
- 890 MHz to 915 MHz: mobile transmit, base receive;
- 935 MHz to 960 MHz: base transmit, mobile receive.
Extended GSM 900 Band, E‑GSM (includes Standard GSM 900 band):
- 880 MHz to 915 MHz: mobile transmit, base receive;
- 925 MHz to 960 MHz: base transmit, mobile receive.
Railways GSM 900 Band, R‑GSM (includes Standard and Extended GSM 900 Band);
- 876 MHz to 915 MHz: mobile transmit, base receive;
- 921 MHz to 960 MHz: base transmit, mobile receive.
DCS 1 800 Band:
- 1 710 MHz to 1 785 MHz: mobile transmit, base receive;
- 1 805 MHz to 1 880 MHz: base transmit, mobile receive.
PCS 1 900 Band:
- 1 850 MHz to 1 910 MHz: mobile transmit, base receive;
- 1 930 MHz to 1 990 MHz base transmit, mobile receive.
- Bluetooth 2450 MHz band
- HIPERLAN 5800 MHz band
- IEEE 802.11 2450 MHz
- IEEE 802.11 5800 MHz bands
Wireless LAN usage
Typical application
The spectrum monitor design is very versatile, applications are wide and varied, however typically With GSM phones getting ever smaller, they are increasingly being used in areas where they may compromise security. GSM and wide band or hopping technologies are becoming the preferred medium for bugs and video surveillance devices.
The Spectrum Monitor design can be used to detect detect activity in these areas, alerting the operator by visual means or viberation, providing covert indication of illicit activity.
For example an LED display can indicate signal strength to assist in location of the source.
Users might include
- Security personnel in Government establishments, military bases, and prisons;
- commercial applications such as banking, dealing rooms, and design offices;
- security companies who need to sweep premises for concealed surveillance devices.
Suggested Features
Variable Sensitivity and detection with graphical or visual indication. The received signal strength of detected signals indicated by the number of LEDs illuminated on the bargraph display. The higher the signal strength, the more LEDs are illuminated.
An audio output to allow modulation signatures to be samples and compared to known sources.
A band switch to allow monitoring of specific bands.