This development was made to shift the original signal band by about the width of this spectrum, plus a small protective band. Only 2 such shifts were made. Thus, the overall band was arranged.
The first image shows the original signal spectrum.
The second figure shows a spectrum shifted.
The spectrum at the output of the digital processing device is shown, without the analog LPF. The second picture shows the 3rd harmonic, which is cut off by the low pass filter.
For electromagnetic compatibility in the transferred bands, it was possible to cut out individual frequencies using configurable rejection filters. The following image shows an approximate view of the device's end-to-end frequency response in the form of the bandpass filter + the rejection filters.
Here you can see 3 rejectors obove the background of the band frequency response.
The low dynamic range is explained by the features of the measuring equipment. :-)