Agilent Technologies PSA Series Manual page 75

The signal source Start Frequency and the Stop Frequency are both
negative. In this case:
2.5E 9 ( )
Source Start Freq
= -------------------------------------------------------------------------------------------------------------- -
Source Stop Freq
=
In this case both the stop and start frequencies are negative, so this
example looks invalid. But in this special case, the PSA can change its
internal mixing to use a negative mixing harmonic. Then the PSA sets
the source start frequency to the positive value of the calculated stop
frequency. It also sets the source stop frequency to the positive value of
the calculated start frequency. This causes the mixing products to
sweep in reverse, and allows the measurement to be made.
Chapter 5
3.0E 9 ( ) 2.5E 9 ( )
⎛
– ( 3.1E 9 ( ) )
-------------------------------------------- -
+ –
⎝
1
3.0E 9 ( ) – ( 3.1E 9 ( ) )
+ +
-------------------------------------------------------------------------------------------------------------- -
1
FAQs and Helpful Hints and Tips
⎞
–
⎠
101 1
–
0.605E 9 ( ) = –605 MHz
= –
3.0E 9 ( ) 2.5E 9 ( )
⎛ ⎞
–
-------------------------------------------- -
⎝ ⎠
101 1
–
=
Hints and Tips
0.095E 9 ( ) = –95 MHz
–
75