Some features of FM antenna design include capable frequencies, line of sight, antenna elements and available capture area. Outdoor FM antennas are highly directional and have greater gain, while indoor antennas feature amplified designs to minimise signal-to-noise ratio.
FM antennas depend on a very high frequency broadcast signal for which a general line of sight of 40 miles is needed. FM antenna design integrates signal sensitivity and features sufficient capture area to receive signals. Taller antennas receive better reception. Outdoor FM antennas feature extra gain that increases signal strength when receiving an FM signal, despite interference. Directional outdoor antennas receive signals of only stations within a specified bandwidth, while omnidirectional antennas with lower gain are designed to work in areas free of multipath problems. Indoor antennas such as the bidirectional dipole and half wave vertical are designed to deal with negative radio frequency attributes.