Integrated four-beam dual-band antenna array fed by broadband Butler matrix

A four-beam dual-band antenna array fed by a single 4×4 Butler matrix is presented, for the first time. A broadband Butler matrix designed in a stripline technique has been used as a basic element of a feeding network. To separate signals frequency diplexers have been designed. All designed elements of the feeding network have been integrated together with two antenna rows operating in two separate frequency bands.