Radio communications are crucial in modern electronics, but the underlying theory can be daunting for hobbyists. This article aims to simplify the concepts, focusing on antennas and electromagnetic waves. By visualizing electric fields using charged particles, the creation of antennas from charged capacitors is explained. Half-wavelength dipole antennas are highlighted for their efficiency and resonance characteristics. The introduction of modulation techniques like AM, FM, and QAM is discussed, with demodulation explained. The inner workings of radio receivers, including mixing signals with sine waves and beat frequencies, are also covered. The superheterodyne receiver, with its intermediate frequency, is highlighted as a common design in modern radios.
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