Carrier Wavelength (L); Path Distance (D); System Losses (L) - ADTRAN 12804108L1A System Manual

Section 2 Microwave Path Engineering Basics
Carrier Wavelength (λ)
The carrier wavelength is the physical wavelength of the main RF carrier being used for communication,
and is usually approximated at the center frequency of the band (which is 2441.75 MHz for the
TRACER 4108 and 5787.5 MHz for the TRACER 4208). The carrier wavelength calculations follow:
λ = c / f (meters)
where
c = speed of light (in meters)
f = frequency (in Hz)
resulting in the following carrier wavelength (at 5787.5 MHz):
λ = 3.00 x 10¯
= 0.0518 m or 5.18 cm

Path Distance (d)

The path distance is simply the physical distance between the transmit and receive antennas. For the
TRACER 4108/4208, these distances can range up to 30 miles.

System Losses (L)

System losses are defined by RF coaxial cable loss, connector losses, and losses added from any additional
lightning protection devices for the power budget analysis. Coaxial cable is required to attach the
TRACER 4108/4208 to the antenna. The length of the cable varies from a few feet to several feet,
depending upon your application and the proximity of the TRACER 4108/4208 to the antenna. Various
grades of coaxial cable will work sufficiently well for connecting the TRACER 4108/4208 unit to the
antenna. A low-loss coaxial cable will minimize cable losses.
One end of the coaxial cable requires an N-type male connector (plug) to mate with the
TRACER 4108/4208 unit. The other end of the coaxial cable requires a connector compatible with
the antenna chosen for the installation (usually an N-type male connector). Additionally, ADTRAN
recommends that the outdoor connector on the coaxial cable be weatherproofed to prevent corrosion
and electrical shorting.
In areas where lightning strikes are frequent, a lightning arrestor should be installed
directly on the antenna coaxial cable. Installing lightning arrestors helps protect the
RF electronics in the downstream path from damaging voltages and currents
(including the TRACER 4108/4208 unit).
18
8 5
/ 5787.5 x 10
© 2003 ADTRAN, Inc.
TRACER 4108/4208 System Manual
612804208L1-1B