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The power of the spectrum shown on the screen will be calculated at first, and two marks are placed on
the spectrum.
The percentage of the power between the two frequency indicated by the mark is specified by the user.
The default percentage for testing is 99%. The power-bandwidth program calculates the power sum of
all signals on the trace at first.
For 99% of the occupied power bandwidth, the markers are placed at the two frequency on the left and
right, and the power between the two frequency accounts for 99% of the total spectrum power. The
remaining 1% of the power is evenly distributed outside the marker. The frequency difference between
the two markers are 99% power bandwidth and displayed on the screen.
The o
ccupied bandwidth
function can also be used to indicate the frequency difference between the center
frequency of the spectrum analyzer and the center frequency of the channel. If the two boundary
frequency of occupied bandwidth are expressed as F1 and F2 respectively, the transmitting frequency
error is defined as the difference between (F1+F2) /2 and the center frequency of the spectrum analyzer.
Occupied bandwidth can be measured in single sweep mode or continuous sweep mode. User must set
the center frequency, reference level and channel interval.
Press
[Meas] >Occupied BW
to enter the following panel menu.
Meas/Setup
:
Avg|Hold Num
（
On/Off
）
: Press average time (on) to specify the average number of sweep to
calculating the measurement results. Sweep time range is from 1 to 999. User can change the average
time by using the numeric key, rotary knob, direction key, or touch the panel menu. Measured average
result will be displayed after the sweeping. Select (off) to turn off this measuring average function.
Avg Mode
（
Exponential/Repeat
）
: Switch between exponential and repetition average mode. When the
specified average time of sweep is reached, this average mode is used to determine the average
operation mode of the spectrum analyzer.
When the exponential average mode is selected, after a specified average time is reached, each
channel trace data is weighted exponentially, added to the previous average value and then take the
average. In the exponential average mode, the weight of the new data is larger than that of the old data,
which is conducive to track signals that change slowly. Measured average result will be displayed after
the sweeping.
When the repetition average mode is selected, after a specified average time is reached, all the previous
data will be delete and restart the sweeping.
Avg Type:
Log-Pwr averaging is to average the logarithmic amplitude values (in dB) of the signal
envelope measured within a signal collection unit, the average detection type will change to video
detection. Power averaging is to average the power of the signal (the square of the amplitude),the
average detection type will change to RMS (power) detection.Voltage averaging is to average the
voltage values of the signal envelope measured in a signal collection unit, the average detection type will
changed to voltage detection, The voltage averaging is still a linear display.
