User's Manual

Table Of Contents
Exalt Installation and Management Guide
EX-i Series (TDD) Digital Microwave Radios
30 206501-019
2016-05-24
Consult the path or site engineer(s) to ensure that the proper materials are chosen for the installation and
that all factors were considered. Refer to the Exalt white paper, Transmission Line for Exalt Indoor
Radio Systems.
Generally, the larger the diameter of the transmission line, the lower the loss. So for longer runs of
transmission line, larger diameter cables are highly advised. However, at every frequency, there is a
maximum diameter cable that supports the operating frequency. Verify the specifications. This is
determined in the path and site planning process.
In some cases, the choice of transmission line is not coaxial cable, but is instead air-dielectric
waveguide. This is an expensive solution and is generally not necessary, but may be required for very
long transmission line runs, and/or very long link distances, and/or for systems requiring extremely high
reliability.
Table 4 lists representative samples of transmission line types recommended for the Exalt Digital
Microwave Radio.
There are several other brands and models of transmission line that are perfectly acceptable. However,
for extremely long transmission lines and/or extremely long radio paths, it may be necessary to use
waveguide transmission line instead of coaxial transmission line. In these cases, waveguide type EW20
is recommended for EX-2.4i models (0.45dB/100ft. loss at 2.4GHz), type EW52 for the EX-4.9i and
EX-5i models (1.2dB/100ft. loss at 5.8GHz, 1.35dB/100ft. loss at 5.3GHz).
It is critical that the transmission line and antenna be capable of supporting the same type of connector,
or easily adapted. It can be important to minimize the number of connectors and adapters, and it is ideal
that they match directly without adaptation. In most cases, transmission line allows for N-type male
connectors and antennas have N-type female connectors. For waveguide, the waveguide flange can
typically accommodate a direct adapter to an N connector, or alternatively, the antenna can be
purchased with a direct waveguide connection. But often a flexible coaxial jumper is required to connect
between the waveguide and antenna, as waveguide is generally inflexible and can be mechanically
challenging to align to the exact antenna connector location.
If possible, connect the primary transmission line directly to the antenna. It is desired to have the fewest
possible pieces of transmission line in the system, to minimize losses and points of failure from
connectors. The antenna can typically accommodate a direct connection if planned in advance. Use a
90º adapter for the connection to the antenna, if necessary, but confirm that all connectors and
transmission lines are properly specified for the operating frequency with minimum loss, proper
impedance (50 Ohm) and proper VSWR characteristics.
Transmission line connector termination is a critical element of the installation. Many ‘factory built’ RF
transmission lines do not provide the proper characteristics for proper transmission, despite their
published specifications, often due to the fully or semi-automated process of factory termination, which
may not have considered the frequency of your system. When buying pre-terminated transmission line,
it is strongly advised to obtain the documentation of test measurements on the connected transmission
Table 4 Recommended transmission line
Manufacturer Type Description Loss at 2.4GHz Loss at 4.9GHz Loss at 5.3GHz Loss at 5.8GHz
Andrew LDF4-50 1/2-inch solid shield 3.3dB/100ft. 5.6dB/100ft. 5.7dB/100ft. 6.0dB/100ft.
Andrew LDF4.5-50 5/8-inch solid shield 2.5dB/100ft. 4.3dB/100ft. 4.4dB/100ft. 4.7dB/100ft.
Times LMR-600 1/2-inch braided shield 4.3dB/100ft. 6.8dB/100ft. 6.9dB/100ft. 7.3dB/100ft.
Times LMR-900 5/8-inch braided shield 2.9dB/100ft. 4.5dB/100ft. 4.6dB/100ft. 4.9dB/100ft.
RFS LCF12-50J 1/2-inch solid shield 3.5dB/100ft. 5.5dB/100ft. 5.6dB/100ft. 5.9dB/100ft.
RFS LCF12-58J 5/8-inch solid shield 2.8dB/100ft. 4.4dB/100ft. 4.5dB/100ft. 4.8dB/100ft.