again tuned to a particular frequency band. Some varieties of RF frequency converters are dual upconverters and downconverters, meaning that they can modulate the frequency either up or down, but ...

or maybe you’re curious about that cheap RF module on AliExpress. Especially in the frequency bands below 1 GHz, you might find yourself interfacing with a module at really low level ...

RF band pass filters are active or passive circuits that pass signals from a specific frequency band and reject signals from out-of-band frequencies. Surface acoustic wave (SAW) filters, crystal ...