A New Class of Antenna Array With a Reconfigurable Element Factor

A parasitic layer-based multifunctional reconfigurable antenna array (MRAA) formed by the linear combination of four (4 x 1) identical multifunctional reconfigurable antenna (MRA) elements is presented. Each MRA produces eight modes of operation corresponding to three steerable beam directions (theta(xz) = -30 degrees, 0 degrees, 30 degrees) with linear and circular polarizations in x - z plane and another two steerable beam directions (theta(yz) = -30 degrees, 30 degrees) in y - z plane with linear polarization. An individual MRA consists of an aperture-coupled driven patch antenna with a parasitic layer placed above it. The surface of the parasitic layer has a grid of 4 x 4 electrically-small rectangular-shaped metallic pixels. The adjacent pixels can be connected/disconnected by means of switching resulting in reconfigurability in beam-direction and polarization. A 4 x 1 linear MRAA operating in the similar to 5.4-5.6 GHz is formed by the optimized MRA elements. MRA and MRAA prototypes have been fabricated and measured. The measured and simulated results agree well indicating similar to 13.5 dB realized array gain and similar to 3% common bandwidth. The MRAA presents some advantages as compared to a standard antenna array: MRAA alleviates the scan loss inherit to standard antenna arrays, provides higher gain, does not need phase shifters for beam steering in certain plane, and is capable of polarization reconfigurability.