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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.
Meas Preset: Reset all parameters of the current measuring mode to factory setting.
Carrier to Noise Ratio
5-7
Figure
Measurement of Carrier-to-Noise Ratio
: carrier power, noise power and carrier-to-noise-ratio.
Measurement of 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,
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