Electronic device with array of antennas in housing cavity

Abstract

Metal housing walls may form an antenna cavity. Antenna structures may be formed from metal traces mounted on a carrier in the antenna cavity. The antenna structures may form an array of antennas such as an array of planar inverted-F antennas. The housing may have an inner cavity wall such as a circular inner cavity wall. The planar inverted-F antennas may lie between the inner cavity wall and the metal walls of the housing. Each planar inverted-F antenna may have an associated parasitic antenna resonating element. The planar inverted-F antennas may be configured to resonate in upper and lower frequency bands. The parasitic elements may each extend inwardly from the metal walls and may broaden the frequency response of the planar inverted-F antennas in the lower frequency band. Parasitic elements may be used to isolate antennas from each other.