Stimulus Setting
The stimulus parameter settings apply to each channel. Before you set the stimulus parameters of a channel, make the channel active.
| Item | Description |
|---|---|
| Note | To make maximize measurement accuracy, perform measurements with the same stimulus settings as were used for calibration. |
Sweep Type Setting
To set the sweep type, use the softkeys.
Sweep Span Setting
The sweep range should be set for linear and logarithmic frequency sweeps (Hz) and for linear power sweep (dBm). The sweep range can be set as either Start / Stop or Center / Span values of the range.
To enter the start and stop values of the sweep range, or center and span, use the softkeys on the Stimulus menu.
| Item | Description |
|---|---|
| Note | If power sweep is activated, the values on the Start, Stop, Center, and Span softkeys will be represented in dBm. |
Sweep Points Setting
The number of sweep points should be set for linear and logarithmic frequency sweeps, and for linear power sweep.
To enter the number of sweep points, use the softkeys.
Stimulus Power Setting
The stimulus power level should be set for linear and logarithmic frequency sweeps. For the segment sweep type, the method of power level setting described in this section can be used only if the same power level is set for all the segments of the sweep. For setting of individual power levels for each segment see section 4.5.9.
To enter the power level value when port couple feature is ON, use the softkeys.
Setting Power Level for Each Port Individually
By default the power levels of all test ports are set to equal value. This function is called Port Couple. The user can optionally disable this function and set the power level of each port individually.
To set the power level for each port individually, first disable the Power Couple function.
Power Slope Feature
The power slope feature allows for compensation of power attenuation with frequency increase, for example in fixture cabling. The power slope can be set for linear, logarithmic and segment frequency sweep types.
CW Frequency Setting
CW frequency setting determines the source frequency for linear power sweeps.
RF Out Function
The RF Out function allows for temporary disabling of the stimulus signal. While the stimulus is disabled, measurements cannot be performed.
To disable/enable stimulus, use the softkeys.
| Item | Description |
|---|---|
| Note | The RF Out function is applied to the whole Analyzer, not to individual channels. Indication of RF Out status appears in the instrument status bar (See section 4.1.3). |
Segment Table Editing
The segment table determines the sweep parameters when segment sweep mode is activated.
To open the segment table, use the Segment Table softkey.
When you switch to the Segment Table submenu, the segment table will open in the lower part of the application. When you exit the Segment Table submenu, the segment table will be hidden.
The segment table layout is shown below. The table has three mandatory columns: frequency range and number of sweep points, and three columns which you can optionally enable/disable: IF bandwidth, power level and delay time.
Each row describes one segment. The table can contain one or more rows. The number of segments is limited only by the instrument’s maximum number of sweep points.
To add a segment to the table, click Add softkey. The new segment row will be entered below the highlighted one.
For any segment it is necessary to set the mandatory parameters: frequency range and number of sweep points. The frequency range can be set either as Start / Stop, or as Center / Span.
To set the frequency range representation mode, click Freq Mode softkey to select between Start/Stop and Center/Span options.
For any segment you can enable the additional parameter columns: IF bandwidth, power level, and delay time. If such a column is disabled, the corresponding value set for linear sweep will be used (same for all the segments).
To enable the IF bandwidth column, click List IFBW softkey.
To set a parameter, make a mouse click on its value field and enter the value. To navigate in the table you can use the keys of the keyboard.
| Item | Description |
|---|---|
| Note | Adjacent segments must not overlap in the frequency domain. |
The segment table can be saved into *.lim file to a hard disk and later recalled.
To save the segment table, click Save… softkey. To recall the segment table, click Recall… softkey.
The segment sweep graph has two methods of frequency axis representation. In the first, the axis displays the frequencies of the measurement points. In some cases it can be helpful to have the frequency axis displayed as sequential numbers. The second method displays the number of the measurement points.
To set the frequency axis display mode, click Segment Display softkey and select Freq Order or Base Order option.
Measurement Delay
Measurement delay function allows for adding an additional time interval at each measurement point between the moment when the source output frequency becomes stable and the start of the measurement. This capability can be useful for measurements in narrowband circuits with transient periods longer than the measurement time per point.
To set the measurement delay time, use the softkeys.