the replacement and elimination of duplexers in a tightly coupled dipole phased array starts with transmit and receive functions physically separated and having different antenna port feeds . the simple coupling network used with tightly coupled dipole arrays is replaced by a state switch which alternates between a coupling state and a dipole feed connection state . the basic method can be applied to antenna apertures of various kinds , including both linear and dual polarized versions . the ability to locate state switches at various nodes in tightly coupled dipole phased arrays permits flexibility in antenna design and eliminates bulky and lossy components , simplifies the design requirements and allows independent optimization of the components .