ADTRAN 6000 Series system manual Transmitted Power PT, Carrier Wavelength λ

Section 2 Microwave Path Engineering Basics TRACER 6000 Series Integrated System Manual

Transmitted Power (PT)

The FCC specifies the maximum transmitter power used for antennae of a given gain. FCC Rules Part 15, Subpart 247 allow for a maximum power of 1 watt (30 dBm) into antennae of a gain less than or equal to 6 dBi. At 2.4 GHz (TRACER 6410), the 1-watt maximum transmitter power must be reduced by 1 dB for every 3 dB of antenna gain over 6 dBi. This rule is shown in Table 5.

Table 5. Transmit Power Reduction for Various Antennae Gains

Output Power	Maximum	Maximum EIRP
	Antenna Gain
(dBm)		(dBm)
	(dBi)
27	15	42
26	18	44
25	21	46
24	24	48
23	27	50
22	30	52
21	33	54
20	36	56

For the 5.8 GHz band (TRACER 6420 L1 and L2), the maximum output power is 1 watt (30 dBm) regardless of the gain of the attached antenna. Since the TRACER 6420 L1 and L2 maximum transmit powers are

100 milliwatts and 250 milliwatts, respectively, there is no reduction in transmitter output power required.

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 2421.7 MHz for TRACER 6410 and 5787.5 MHz for the TRACER 6420). 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 wavelengths
TRACER 6410	TRACER 6420
λ = 3.00 x 108 / 2421.7 x 106	λ = 3.00 x 108 / 5787.5 x 106
= 0.124 m or 12.4 cm	= 0.0518 m or 5.18 cm
= 4.88 in	= 2.04 in

20 Copyright © 2005 ADTRAN, Inc. 612806420L1-1F