An electronic device may have a first conductive sidewall at an upper end, a second conductive sidewall at a lower end, and a conductive rear wall. First and second antennas may be formed at the upper end and may include slots with edges defined by the first sidewall and the rear wall. Third, fourth, fifth, and sixth antennas may be formed at the lower end and may include slots with edges defined by the second sidewall and the rear wall. Each antenna may cover multiple frequency bands. First order and third order modes of the slots may contribute to the frequency responses of the third through sixth antennas. A display controller may be mounted at the lower end and may impose a lower limit on the frequencies covered by the third through sixth antennas. The first and second antennas may cover lower frequencies than the third through sixth antennas.