Antennas; Coaxial Cable - Microhard Systems Nano IP Series Operating Manual

7.0 Installation

7.2.1 Antennas

The two most common types of antenna are the omnidirectional ('omni') and directional (Yagi).
Direct human contact
with the antenna is
potentially unhealthy
when a Nano IP is
generating RF energy.
Always ensure that the
The network topology, application, and path calculation are all taken into consideration when
Nano IP equipment is
selecting the various antenna types to be used in a radio network deployment.
powered down (off)
during installation.
In a long-range PTP network, Yagi antennas should be considered. There antennas will provide
for the most focused ‗RF connection' between the two sites.
In a PMP network where remotes are located in all directions from the Master, the Master site
will have an omni so that it can communicate with all remotes; the remotes, however, may all
employ Yagi antennas ‗pointed at' the Master.
Typically a Repeater site will employ an omni such that it can readily receive an RF transmission
from one direction and be able to readily transmit it in another.
If an application involves remotes which are not stationary (e.g. mobile application), all sites
would likely use omni antennas so that wherever the units may be, there should be antenna pat-
tern coverage.
The path calculation (see Section 7.1) will determine the antenna gain requirements. Refer to
the beginning of this section to review the various factors which must be considering when de-
To comply with FCC
ploying a network. Do not discount the importance of the REQUIRED HEIGHT for the antennas
regulations, the
within your network.
maximum EIRP must
not exceed 36dBm.

7.2.2 Coaxial Cable

The following types of coaxial cable are recommended and suitable for most applications
(followed by loss at 900MHz, in dB, per 100 feet):
For a typical application, LMR 400 may be suitable. Where a long cable run is required - and
in particular within networks where there is not a lot of margin available - a cable with lower
loss should be considered.
When installing cable, care must be taken to not physically damage it (be particularly careful
with respect to not kinking it at any time) and to secure it properly. Care must also be taken to
affix the connectors properly - using the proper crimping tools - and to weatherproof them.
© Microhard Systems Inc.
An omni typically has 3-6dBi gain and spreads its energy in all directions (hence the
name 'omnidirectional'). The 'pattern' of the energy field is in the shape of a donut, with
the antenna mounted vertically at the centre. This vertical-mounted antenna produces a
signal which is vertically 'polarized'.
A Yagi has a more focused antenna pattern, which results in greater gain: commonly, 6
-12dBi. The pattern of a Yagi is in the shape of a large raindrop in the direction in which
the antenna is pointed. If the elements of the Yagi are perpendicular to the ground
(most common orientation) the radiated signal will be vertically polarized; if parallel to
the ground, the polarization is horizontal.



CONFIDENTIAL
LMR 195 (10.7)
LMR 400 (3.9)
LMR 600 (2.5)
140