The present invention provides 'an antenna having a symmetrical switching architecture'. An electronic device may include wireless circuitry with antennas. An antenna resonating element arm for an antenna may be formed from conductive housing structures running along the edges of the device. The antenna may have first and second antenna feeds and multiple adjustable components that bridge a slot between the antenna resonating element and an antenna ground. A control circuit may control the adjustable components and selectively activate one of the first and second feeds at a given time to placethe antenna in first, second, or third operating modes. The control circuit may determine which operating mode to use based on information indicative of the operating environment of the device. By switching between the operating modes, the control circuit may shift current hot spots across the length of the resonating element arm to ensure satisfactory performance of the antenna in a variety of operating conditions.