Solving FM Antenna Design Challenges in Portable Devices

FM radio has witnessed an explosion of interest from the market for its applications in mobile and personal media players; however, the traditional FM design approach requires a long antenna, such as a wired headphone, which limits its usefulness and usability. This white paper provides a description of an FM radio receiver solution that enables the antenna to be integrated or embedded inside the portable device enclosure, making the headphone cable optional. This paper covers techniques for maximizing sensitivity, including maximizing efficiency at the resonant frequency and maximizing efficiency across the FM band with a tunable matching network.