Abstract: An antenna device, a wireless cellular network, and a method of capacity expansion are provided. The antenna device includes: a contact element adapted to connect a base station to receive input signals from the base station; an amplitude and phase allocating element adapted to allocate the input signals received by the contact element according to designed amplitudes and phases; an antenna element comprising an array of antennas comprising an even number of columns, and adapted to receive and transmit the input signals allocated with the amplitudes and phases. An array of antennas comprising an even number of columns has been adopted, and a feed network construction of the antenna system has been improved, so that through adjusting amplitudes and phases of original signals from a base station, a smooth capacity expansion of the network can be achieved without adjusting antenna directivities, thus reducing the workload and complexity for capacity expansion.