One of the topics covered in this chapter is a quick review of image signals. These are radio-frequency (RF) signals within the band of interest that can mix into the intermediate-frequency (IF) stages and cause interference in the manner of having two radio stations’ signals demodulated at the detector or having a single station that pops up in two places within the band. We will examine how image signals are reduced via tuned circuits from the beginning days of the superheterodyne radio to using I and Q signals in an image reject mixer. Finally, an image-rejection mixer using I and Q signals will be analyzed.
Therefore, the objectives of this chapter are
1. To explain image signals
2. To show methods to reduce image ...