RF

What Actually Receives a Radio Signal: Antenna, Tuning, Detection, and Amplification

A radio receiver does not begin with a transistor. It begins at the antenna terminals, where an electromagnetic field produces a small RF voltage and current that the rest of the circuit can process. That distinction matters in discrete-transistor projects. An antenna, a tuned network, a detector, and an amplifier perform different electrical jobs. Combining their names into “the radio circuit” hides the boundary that determines whether a receiver can select a station, recover its modulation, and produce enough output to hear.