Anritsu S113C User Manual
In-Band/Out-of-Channel Measurements
The in-band/out-of-channel measurements are those measurements that measure distortion
and interference within the system band, but outside of the transmitting channel. These
measurements include in-band spurious emissions and adjacent channel power ratio (also
known as spectral regrowth). There are stringent regulatory controls on the amount of inter-
ference that a transmitter can spill to neighboring channels. In order to determine compli-
ance with the allowable level of spurious emissions, the spectrum analyzer needs two
parameters to be specified:
and interference within the system band, but outside of the transmitting channel. These
measurements include in-band spurious emissions and adjacent channel power ratio (also
known as spectral regrowth). There are stringent regulatory controls on the amount of inter-
ference that a transmitter can spill to neighboring channels. In order to determine compli-
ance with the allowable level of spurious emissions, the spectrum analyzer needs two
parameters to be specified:
q
Measurement channel bandwidth
q
Allowable level of spurious emissions.
Required Equipment
q
Site Master Model S114C or S332C
q
30 dB, 50 Watt, bi-directional, DC –18 GHz, N(m) – N(f), Attenuator
q
Test Port extension cable, Anritsu 15NNF50 – 1.5C
Procedure
Step 1. Using the test port extension cable and 30 dB attenuator connect the Site Master
to appropriate transmit test port.
Step 2. Press the
ON/OFF
key on the Site Master.
Step 3. Press the
MODE
key.
Step 4. Use the Up/Down arrow key to select the Spectrum Analyzer mode and press
ENTER
.
Step 5. Select the center frequency for the channel of interest.
Step 6. Set the frequency span wide enough to include the primary channel and upper
and lower channel.
Step 7. Set the following parameters as specified:
reference level = 0 dBm
input attenuation level = auto
resolution bandwidth =10 kHz
video bandwidth =300 Hz
input attenuation level = auto
resolution bandwidth =10 kHz
video bandwidth =300 Hz
Step 8. Use the limit line and markers to read and compare observed signals to the spec-
ified allowable level of in-band spurious emissions for the corresponding chan-
nel transmitted frequency.
nel transmitted frequency.
NOTE: The resolution bandwidth of a spectrum analyzer is determined by the
intermediate frequency (IF) filter bandwidth. Site Master, as do conventional
spectrum analyzers, traces the shape of the IF filter as it sweeps past a signal.
Therefore, if two equal-amplitude signals are very close to each other, the mea-
surement result can appear to be one single response because the IF or resolu-
tion bandwidth is not small enough to resolve the two signals. Similarly, if two
signals are not equal in amplitude but are very close together, the smaller sig-
nal may not be seen because it is hidden under the large response.
intermediate frequency (IF) filter bandwidth. Site Master, as do conventional
spectrum analyzers, traces the shape of the IF filter as it sweeps past a signal.
Therefore, if two equal-amplitude signals are very close to each other, the mea-
surement result can appear to be one single response because the IF or resolu-
tion bandwidth is not small enough to resolve the two signals. Similarly, if two
signals are not equal in amplitude but are very close together, the smaller sig-
nal may not be seen because it is hidden under the large response.
5-7
Chapter 5 Spectrum Analyzer Measurements