How-To Guide

Privaris, Inc. Gate & Vehicle Solution
02.14.08
Page 3 of 3
directional if this is needed. The 50 deg SMC antenna is recommended this for installations that
are a “generic” single lane.
This antenna in a standard set up was able to communicate at about 25 degrees off center
providing about a 50 degree cone of reception. Like all antennas, there are side lobes that allow
you to communicate in about a 10 foot circle around the antenna with no attenuation. The
approximate pattern is a 10 foot circle around the antenna with a 50 degree beam width beyond
that. The test data was collected using the following criteria:
∙ In a car with all windows rolled up
∙ plusID device held in right hand above dashboard
The baseline was obtained using a standard set-up with no attenuation; the plusID 90 was held
above the dash board at a 45 degree angle and communicated with the lane transceiver with a 2-
3 second delay resulting in a confirmed maximum range of ~300 feet. At 300 feet there is
approximately 250 feet of side to side range as shown in the diagram below. As the distance to
the SMC antenna or attenuation decreases the plusID 90 becomes less orientation and position
dependent as the signal strength increases and provides faster connections time (usually less
than 1 sec).
*
This is an approximation of a complex antenna pattern.
∙ With 10 dBi of attenuation there was not an appreciable reduction in performance when
measured at the maximum range of 300 feet.
∙ With 16 dBi of attenuation the maximum range was reduced to 90 feet.
∙ With 20 dBi of attenuation the maximum range was reduced to 36 feet.
Based on these measurements it is estimated that 18 dBi of attenuation will give about 50 feet of
range and 15 dBi of attenuation will give about 100 feet of range.
50 deg
300 ft
200 ft
100 ft
50 ft
~250 ft
~160 ft
~75 ft
~35 ft
SMC
Antenna