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 × 1) identical multifunctional reconfigurable antenna (MRA) elements is presented. Each MRA produces eight modes of operation corresponding to three steerable beam directions (θ
xz
=-30
^°
, 0
^°
, 30
^°
) with linear and circular polarizations in
x
-
z
plane and another two steerable beam directions (θ
yz
=-30
^°
, 30
^°
) 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 × 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 × 1 linear MRAA operating in the ~ 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 ~ 13.5 dB realized array gain and ~ 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.