I am surprised how the Superheterodyne Receiver still works and is still in use after coming to realise the impact of Image Frequencies on its performance. Basically, I'm curious how engineers make such an architecture work despite the affect made by Image Frequencies at multiplication stage of Super Heterodyne Architecture. I illustrate the affect of Image Frequencies using the following diagram.
As seen, It seems our intelligence on right hand side can be destroyed by the Image Frequencies (whole band of it) standing to the left side to the LO once both signals go through the mixer. I think this is an unavoidable scenario because making Band Pass Filters to eliminate signals close to the left hand side of LO is not practical.
Imagine a busy band such as 868MHz. The complete spectrum is busy and filled with very closely spaced out powerful transmissions. In such cases, I can be certain that there will definitely be powerful signals to the left of my LO. Hence, the resulting down converted difference frequency band will always represent both bands to surrounding the LO. This can be more clearly seen by the figure below.
I am very interested to know how engineers despite this phenomena still make excellent use of this architecture. What am I missing?
Please note that I am fully aware that this problem is eliminated in the later Homodyne architecture. But I would like to make my question very specific to this architecture.
Thanks for your answer/s.