HP 84125C, User Manual

Page: 67 / 101

Note
This procedure describes the FCC requirement. Measurements to
other regulatory standards would be similar but should use the
limits , measuring distances , and procedures described in those
regulations .
Even though the measurement is done specically for harmonic
emissions , any spurious emission from the test device that exceeds
the limit also fails the specication.
If measured results using peak detection are signicantly below
the limit line (approximately 6 dB), further measurements are not
required.
Conguring the T est Set
1. Determine the fundamental frequency of the equipment under test
(EUT). F or this example , a fundamental frequency of 830 MHz will
be used for the cellular telephone , an intentional radiator .
2. Make a list of the harmonic frequencies that you will need to test.
F or 830 MHz, the ten harmonic frequencies to be tested are:
1.66 GHz
2.49 GHz
3.32 GHz
4.15 GHz
4.98 GHz
5.81 GHz
6.64 GHz
7.47 GHz
8.30 GHz
3. The fundamental signal is usually 40 dB above the harmonics . In
order to avoid overloading the spectrum analyzer rst converter ,
a high-pass lter must be added. T o lter out the fundamental
frequency of 830 MHz, install the 1.5 GHz lter in the test set
and ensure that the 1 to 18 GHz antenna is installed. Refer to
Figure 4-2 to assist you with this procedure .
4. On the spectrum analyzer , press the following key sequences:
a.
4 PRESET 5 , 4 MODULE 5 ,
N NNNNNNNNNNNNNNNNNNNNNNNNNNNN
USER KEYS
b.
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
HP84125C Config ,
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
1.5GHz to 18GHz
This selects the amplitude correction factors for the 1.5 to
18 GHz lter signal path and the 1 to 18 GHz horn (from 1.5
to 18 GHz). The resolution bandwidth is set to 1 MHz and the
video bandwidth is set to 3 MHz.
6-2 Making Measurements