Digital Microwave Overview and Advantages

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The MWx PRO series of microwave sensors
    
Integrated Security Corp is proud to offer the outstanding digital microwave sensors manufactured  by our Italian partner, Cias Elettrònica.  These bi-static (transmitter/ receiver pair) sensors operate in the X-band and use digital processing to provide the highest level of performance in the industry.  Available in models with ranges of 50m-80m-120m-200m, they are amazing performers that will exceed your expectations.
 
                                 



Digital Processing

Other microwave sensors operate in analog mode.  They simply look for a significant disturbance in the microwave signal to create an alarm.  

The MWxPRO sensors only start their work when a disturbance is noticed. Looking at the wave pattern generated while the disturbance is occurring, they decide if it is a real alarm or a nuisance event that can be ignored.  How do they do that?  Using “fuzzy logic”, the size, shape and rate of change of the observed signal is compared to hundreds of stored patterns corresponding to known alarm types.  If there is a close match, an alarm is generated.  Intruders walking, running or rolling will be caught. All disturbances, whether or not they are recognized as alarms, are date and time stamped and stored in the receiver for later analysis.

What kinds of things don’t cause nuisance alarms when you use these sensors, even though their sensitivity is set high?  How about small animals, birds, fog, and the reflection off pooled water?  All of these can create alarms with old analog style sensors until you lower their sensitivity to a dangerously low level.




Clean Strong Signal
    
The MW482 microwaves use a parabolic antenna with linear polarization.  The parabolic antenna allows for the head to be rotated through 90º in very demanding installations to avoid sources of interference at crossover points.  Older microwave sensors typically have elliptical or planar antennas with circular polarization, and see no change if the antenna is rotated in this way.  Furthermore, the parabolic antenna allows a stronger cleaner received signal compared to analog microwave systems.

Relying on this clean strong signal, the MX482 detectors have outstanding anti-masking capability.  Placing a false transmitter in front of the receiver in an attempt to shield an intruder will be immediately detected as a change in signal strength.


 

Narrowing the detection field
The MWxPRO detectors can operate in tight confines that would make older microwaves useless due to nuisance alarms.  Typical cases are where the microwave sensors must be run between fence lines or along roadways or tree lines.  There are two ways MWxPRO can defeat this problem.  First, there are alternate antennas that can be used to physically narrow the field of microwave radiation.  Second, “fuzzy logic side target discrimination” analysis of signal strength allows the sensors to recognize disturbances only occurring at the edge of the field of view and not crossing through it, as in a waving tree branch or loose moving chain link fence fabric.  

                                             
 
Fuzzy Side Target Detection Pattern                                          Detection Pattern Typical of Older Sensors
 



 Between Fence Lines


Signal Interference

The MW 482xPRO is not affected by interference from airport radars or from environments where there are powerful military microwave frequency transmissions. Installations using MW482xPRO microwaves in civil aviation and at military airports are a testament to this statement. The MW482xPRO operates in the X-band which provides improved volumetric range and protection of the detection zone.

At crossover points, the potential for interference is reduced by having four pre-settable modulation codes or channels available.  In complex environments, the sensors can operate at any of sixteen different frequencies, which can actually be in effect doubled, by rotating parabolic antennas 90° to take advantage of the linear polarization.


                                                                      
                At an Airfield                                                                                                     Crossover  Point
 


Automatic Adjustment to Environment

Temperature is continuously monitored to detect faults.  In addition, temperature change over time is monitored and compensation is made for signal differences created by those changes.


 

Set Up and Adjustment
    
The MW482xPRO incorporates built-in audio and visual set-up aids.  It also includes a walk test function that identifies the actual protection zone and provides the installer with a true feel of the detection area.

For more sophisticated control and analysis, we offer MW Manager software.  The receiver head has an RS-485 link for connection to either a portable computer brought to the sensor, or via the appropriate network connections, to a computer anywhere in the world.