Limitless™ WPMM Series
Issue 2
50051864
Honeywell Sensing and Control
22
ATTENTION
The antenna cables should not be modified (i.e. cut short and/or re-terminated) as it may affect
Communication Agency approval.
WARNING
The WPMM must be installed in accordance with the requirements specified in this document. See Section 3
and Section 4 for EIRP requirements. Only the specified EIRP power settings, antenna types and gains, and
cable lengths (attenuation) as outlined in this document are valid for Limitless™ WPMM Series installations.
7.1.1
Omni-directional Antenna Design
The omni-directional antennas offered in the Limitless™ Series were chosen for their ability to be used in
applications where transmit-and-receiver antennas may be moving with respect to each other or could also be
stationary. They are dipole antennas that radiate power (power from the internal radio of the WPMM monitor) in a
360° outward pattern in a plane perpendicular to the length of the antenna element. “Omni” may suggest the
antenna radiates power in all directions, but that is not the case. The actual antenna radiation pattern looks more
like a toroid (doughnut-shape) as shown in Figure 12.
Figure 12. Radiation Pattern of an Omni-directional Antenna
Toroid Radiation Pattern -
Pattern is 360 degrees in the vertical
plane, but not the horizontal plane
2.2 dBi RF Antenna Pattern -
Horizontal
2.2 dBi RF Antenna Pattern -
Vertical
The antenna radiates virtually zero power in the Z axis and most of the power in the X and Y axis. Increasing the
antenna’s gain will increase the power only in the X and Y axis. As a result, the radiation pattern becomes more
narrow. For instance, this is analogous to the reflector in an automobile’s headlight. The reflector does not add light
or increase the luminous intensity of the light bulb, rather it simply directs all the light energy in the forward direction
where the light is needed most.
