In a broadband dual polarized base station antenna for IMT-Advanced systems

The invention discloses a base station antenna that is applied to an international mobile telecommunication-advanced (IMT-Advanced) system of a fourth generation wireless mobile communication system. The antenna unit employs a mode of multi-layer microstrip paster antenna and a basic structure of the antenna comprises a metal reflecting plate, a microstrip feeding layer, two radiating layers and a plurality of nylon insulating columns. The greatest innovation of the invention lies in an ultrabroad band characteristic of the antenna; a novel arrowhead coupling feeding groove and a double-layer radiation patch are employed; and a bandwidth can reach 49.5% on the condition that a standing-wave ratio is less than 1.5. On the basis of a reasonable design of a reflecting plate, a half-power lobe width of the antenna is a value caused by adding 6 degrees to 65 degrees or by subtracting 6 degrees from 65 degrees in a whole working frequency band range; and a convergence degree of a wave beam of the antenna has a good performance. According to the invention, a corner feeding mode is employed to carry out feeding and a dual polarization with plus/minus 45 degrees is realized on the condition that it is avoided that a radiation patch is rotated by 45 degrees, so that it is beneficial to reduce a whole length of an antenna array after arrangement of the array. On the basis of the basic structure that is based on the technical scheme of the invention, other concrete embodiments of the invention can be constructed only by reasonably changing a size of a radiation patch, a shape of a slotted floor and spaces between all layers.