User’s Manual UTS1000B/T Series
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Measurement of Carrier-to-Noise Ratio
: carrier power, noise power and carrier-to-noise-ratio.
Search for the maximum positive peak f1 as the carrier within the screen range, calculating the power
within the carrier bandwidth centered at f1, take it as the carrier power. Set frequency offset to make no
carrier signal in the noise bandwidth.
Calculating the power within the noise bandwidth centered on f1 + frequency offset, take it as noise power.
Divide the carrier power by the noise power, the result is the carrier-to-noise ratio.
Press [Meas] >CNR 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.
Carrier BW: Set the bandwidth of the carrier to be measured. The carrier bandwidth is linked with sweep
width, noise bandwidth and frequency offset. User can change the carrier bandwidth by using the numeric
key, rotary knob, direction key, or touch the panel menu.
Noise BW: Set the bandwidth of the noise to be measured. The noise bandwidth is linked with sweep width,
noise bandwidth and frequency offset. User can change the noise bandwidth by using the numeric key,
rotary knob, direction key, or touch the panel menu.
Offset Freq: Set the difference between the center frequency of carrier and the noise. The frequency offset
is linked with the sweep, carrier bandwidth and noise bandwidth. Users can change the frequency offset by
using the numeric key, rotary knob, direction key, or touch the panel menu.
