ADTRAN 12804108L1A System Manual

Section 2 Microwave Path Engineering Basics TRACER 4108/4208 System Manual18 © 2003 ADTRAN, Inc. 612804208L1-1BCarrier 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 theTRACER 4108 and 5787.5 MHz for the TRACER 4208). The carrier wavelength calculations follow:λ = c / f (meters)wherec = speed of light (in meters)f = frequency (in Hz)resulting in the following carrier wavelength (at 5787.5 MHz):λ = 3.00 x 10¯8 / 5787.5 x 10 5= 0.0518 m or 5.18 cmPath Distance (d)The path distance is simply the physical distance between the transmit and receive antennas. For theTRACER 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 additionallightning protection devices for the power budget analysis. Coaxial cable is required to attach theTRACER 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. Variousgrades of coaxial cable will work sufficiently well for connecting the TRACER 4108/4208 unit to theantenna. 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 theTRACER 4108/4208 unit. The other end of the coaxial cable requires a connector compatible withthe antenna chosen for the installation (usually an N-type male connector). Additionally, ADTRANrecommends that the outdoor connector on the coaxial cable be weatherproofed to prevent corrosionand electrical shorting.In areas where lightning strikes are frequent, a lightning arrestor should be installeddirectly on the antenna coaxial cable. Installing lightning arrestors helps protect theRF electronics in the downstream path from damaging voltages and currents(including the TRACER 4108/4208 unit).