Example 5: Offset Causes Bad Source Stop Frequency; Example 6: Offset Causes Valid Negative Source Settings - Agilent Technologies PSA Series Manual

Hints and Tips
FAQs and Helpful Hints and Tips

Example 5: Offset Causes Bad Source Stop Frequency

Using PSA (13.2 GHz and above) and a 6 GHz source (for example, an
E4438C):
PSA settings:
• Start Freq = 10 GHz
• Stop Freq = 12 GHz
• Sweep Points = 101
• Offset = −5 GHz, On
• Harmonic = OFF
This will cause the "Freq range of ext src exceeded" error.
Reason:
The signal source is being asked to sweep outside its frequency range.
In this case:
10E 9 ( )
Source Start Freq
= ----------------------------------------------------------------------------------------------------- -
12E 9 ( )
Source Stop Freq
= ----------------------------------------------------------------------------------------------------- -
But 7.02 GHz is not in the range of the signal source.
So the offset or stop frequency should be changed until the calculation
is less than the source maximum frequency. (Find the source maximum
frequency using the PSA command
SOURce:EXTernal:FREQuency:STOP? MAX)

Example 6: Offset Causes VALID Negative Source Settings

Using any PSA and any source:
PSA settings:
• Start Freq = 2.5 GHz
• Stop Freq = 3.0 GHz
• Sweep Points = 101
• Offset = −3.1 GHz, On
• Harmonic = OFF
This will not cause the "Freq range of ext src exceeded" error.
Reason:
74
12E 9 ( ) 10E 9 ( )
⎛
–
– ( 5E 9 ( ) )
----------------------------------------- -
+ –
⎝
101 1
1
12E 9 ( ) 10E 9 ( )
⎛
– ( 5E 9 ( ) )
----------------------------------------- -
+ +
⎝
101 1
1
⎞
⎠
–
4.98E 9 ( ) = 4.98 GHz
=
⎞
–
⎠
–
7.02E 9 ( ) = 7.02 GHz
=
Chapter 5