Huygens Pattern-Reconfigurable Antenna Array With Wide Beam-Steering Angle and Stable-Enhanced Gain

In this communication, a pattern-reconfigurable antenna (PRA) array with wide beam-steering angle and stable-enhanced gain based on Huygens sources is presented. It consists of a cascaded
$1 \times $
magnetic dipole (MD) array and an in-phase
$2 \times $
electric monopole (EM) array. The MD array is realized as TE
$_{(1/2)01}$
-mode substrate-integrated waveguide (SIW) cavity with meander-type phased inverters and a single port. The EM array, composed of six trapezoidal metal patches, is orthogonally located along both sides of the SIW cavity. In addition, the EM array is connected/disconnected to the SIW cavity by six p-i-n diodes. The MD array and EM array form a pair of Huygens sources, which provide the foundation for reconfigurable patterns. By controlling the on/off states of p-i-n diodes, a nine-type Huygens source array with different tilted beams is realized. The measured overlapped impedance bandwidth of the proposed antenna is 280 MHz from 4.62 to 4.9 GHz. Across the whole bandwidth, the measured realized gain is stable with a 9.66-dBi peak value. Besides, when the different reconfigurable patterns are steering, the E-plane pattern can cover 162° beamwidth with a fluctuation of less than 1 dB. Compared with the existing PRA-based beam-steering arrays, the proposed design provides a wide beam-steering angle, stable gain, and simple feeding method.