Dual TX/RX 8/spl times/4 sub-arrays for phased array antenna

For the purpose of miniaturization of antenna system, a dual TX/RX sub-array antenna is necessarily required. To do this, polarization diversity techniques with orthogonal feeds are commonly used. The definite implementations of feeding network have a form of coplanar or separated layer representation Generally, in case of a dual sub-array of two dimensional form, its feeding layers should be separated, e.g. microstrip direct and aperture coupled feed. And also this scheme has good isolation characteristics between two ports. Furthermore for the requirements of the wide bandwidth and high directivity, the stacked patch configurations are adopted to satisfy above two requirements and for a simplicity of extension to array. In this work, we proposed the dual feeding structure with microstrip and aperture coupled feed. TX, RX frequency ranges are from 14.0 to 14.5 GHz and 11.7 to 12.75 GHz respectively.