User's Manual

Skybitz Inc
MTXM
FCC/IC Test Report
November, 2009
WLL Report #11125-01 Rev. 3 - Page 7 of 40 - © 2009 Washington Laboratories, Ltd.
4 Test Results
4.1 RF Power Output (FCC 25.204, RSS-170 Section 6.2)
FCC 25.204 specifies the limits for Satellite Earth Stations.
In bands shared coequally with terrestrial radio communication services, the equivalent isotropically
radiated power transmitted in any direction towards the horizon by an earth station operating in
frequency bands between 1 and 15 GHz, shall not exceed the following limits:
+40 dBW in any 4 KHz band for θ: 0°
+40+3 θ dBW in any 4 KHz band for θ <0°≤05°
Where, θ is the angle of elevation of the horizon viewed from the center of radiation of the
antenna of the earth station and measured in degrees as positive above the horizontal plane and
negative below it.
IC RSS-170 Section 6.2 and Annex B specify the following requirements:
The output power shall be measured when the transmitter is operating at the manufacturer’s rated
power and modulated with signals representative (i.e. typical) of those encountered in a real system
operation. This measurement shall be carried out before the other tests.
If the power is in bursts, the power shall be averaged over any 100 millisecond interval, or over the
burst interval if the burst is shorter than 100 milliseconds, during which its value is at its maximum.
Record the output power.
4.1.1 Power measurement test procedure – Signal Substitution Method
No direct connection to the antenna is available for making the power measurement as the antenna is
integrated with the unit.
To measure the EIRP the EUT was placed on motorized turntable for radiated testing on a 3-meter
open field test site. The emissions from the EUT were measured continuously at every azimuth by
rotating the turntable. Receiving antennas were mounted on an antenna mast to determine the height of
maximum emissions. The height of the antenna was varied between 1 and 4 meters. Cables were
varied in position to produce maximum emissions. Both the horizontal and vertical field components
of the EUT were measured.
The received level of the detected emission was recorded in the data sheet. The EUT is then replaced
with a transmit antenna and signal generator. Output power of the signal generator was increased until
the same received level was indicated on the spectrum analyzer for the emission under investigation.
Radiated power of the emission was then determined by adding the forward power supplied to the
substitution antenna with the gain of the substitution antenna and comparing the result to the limit.