Instructions

RF Explorer Signal Generator User Manual page 32
Harmonics filtering
Harmonics are integer multiple frequencies of the main CW output frequency, and is a common sub-product
of RF circuits of all kinds. In some cases, the harmonics are intended useful output signal but, in most cases,
they are undesired and can cause intermodulation and false output reading in Spectrum Analyzers.
RF Explorer Signal Generator RFE6GEN baseline includes no internal harmonic filtering, and is intended for
use in Tracking SNA and other purposes where harmonics are not an issue. Specifically tracking uses an
iterative, computer control sweep where the harmonics are fully ignored and have no side effect, making
RFE6GEN the lower cost option to perform these tasks.
For more demanding uses where harmonics signals are not welcome, the RF Explorer Signal Generator
Combo model includes a sophisticated yet compact filter bank to significantly reduce the output power of
harmonic signals.
An example of the improvement offered by the Combo model is depicted below:
Example output
signal including
harmonics from a
25MHz CW signal in
RFE6GEN baseline
model.
Note odd value
harmonics 3
rd
, 5
th
,
7
th
, etc are in range
of -12 to -19dBc
These signals are not
an issue when using
Tracking SNA but
may be undesired in
other scenarios.
As comparison the output signal from the new filtered Combo model is depicted below.
Note with the new Combo model only 3
rd
harmonic is measurable, and attenuated to the range of -50dBc,
where other higher order harmonics are no longer above noise floor.