Agilent Technologies PSA Series User And Programming Manual page 68

Instrument Functions: A - L
Auto Couple
Remote Command:
[:SENSe]:ADC:RANGe AUTO|NONE
[:SENSe]:ADC:RANGe?
Remote Command Notes:
Example:
ADC:RANG NONE
2.2.7.1 Autorange
Turns the ADC ranging to automatic which provides the best signal to noise ratio. Auto
Couple All sets the ADC ranging to Autorange. Autorange is usually preferred over
Bypass.
Key Path:
Auto Couple
State Saved: Saved in Instrument State
Remote Command:
Example:
ADC:RANG AUTO
2.2.7.2 Bypass
Turning the ADC ranging to bypass mode allows higher throughput for FFT
measurements. (It can improve FFT measurement speed by 10% to 50%.) Bypass also
provides better phase noise, though the effect is negligable when using swept analysis or
for offsets below 300 kHz. The £(f) improvement is a few dB in FFT mode at 800 kHz offset.
allows triggered FFT measurements to occur at the trigger time instead of
Bypass
following an autoranging time. Therefore, whenever the trigger selected is anything other
than , and the
Free Run
Bypass regardless of the setting of ADC Ranging. See
With Your PSA" on page
which may be visible with very high signal levels at the input mixer.
Key Path:
Auto Couple
State Saved: Saved in Instrument State
Remote Command:
Example:
ADC:RANG NONE
68
sweep selection is made, the ADC hardware is set to
Manual:FFT
61. Another advantage of Bypass is lower IF harmonic distortion,
"Making Gated FFT Measurements
Chapter 2