Millimetre-wave beam-switching rotman lens antenna designs on multi-layered LCP substrates

Compact and low-cost antenna arrays with beamsteering or beam-switching are needed for emerging millimeter-wave communication systems such as 5G and WLAN at the 60 GHz frequency band. The Rotman lens is a planar lens which can be used in conjunction with an antenna array to provide several switchable beam directions. The Rotman lens is a truetime delay device which makes it ideal for wideband systems. The proposed concept can be integrated on a printed circuit board construction based on liquid crystal polymer (LCP) base materials. The design, manufacturing and measurement results are presented for a 60 GHz Rotman lens implementation. The presented design can electrically switch between five different beam directions −30°, −15°, 0°, 15° and 30°.