Other topics about Optimizing Measurements
The Shift LO mode is used to set the local signal (LO). Generally, the E5072A sets the local signal (LO) as RF+IF. However, this causes image response at certain frequencies. To reduce the unnecessary image response, the LO mode allows you to select the local signal (LO).
Shift LO mode should be turned ON for frequencies below the centre frequency of the bandpass filter and turned OFF for frequencies above the centre frequency of the bandpass filter.
Shift LO mode ON: LO = RF-IF
Shift LO mode OFF: LO = RF+IF
This function is not available for frequencies below 150 MHz.
To turn on the Shift LO Mode, follow the steps below:
Press Sweep Setup
Click Max Freq to set the maximum frequency
When Shift LO mode is turned ON, the "Shift LO" indicator is displayed on the channel status bar.
System calibration (adjustment) is not taken into account when Shift LO mode is ON. Calibration should be performed before your measurement. If this function is turned on after a calibration, “Cor” is changed to “C!” on the channel status bar.
The table below describes the conditions for which Shift LO is available/unavailable:
|
Function |
Note |
|
FOM |
Shift LO is not available when FOM (Frequency Offset) is ON. Both Shift LO and FOM cannot be set to ON at the same time. |
|
Arbitrary Sweep |
Shift LO is available with arbitrary sweep. However, if your setting requires large data sizes, an overflow error may occur. In that case, reduce the measurement data size (i.e. NOP, number of channels) |
|
Sweep Mode |
Shift LO is available in all sweep modes (Step/Swept) |
|
Sweep Type |
Shift LO is available in all sweep types (Lin/Log/Segment Sweep/Power). If List Shift LO in Segment Sweep (Edit Segment Table > List Shift LO) is OFF, the setting of Sweep Setup > Shift LO Mode > Shift LO Mode is used. |
Sets the maximum frequency for the measurement sweep. By default, the maximum frequency is set to the maximum frequency of the E5072A.