Frequency- and Pattern-Reconfigurable Antenna Array With Broadband Tuning and Wide Scanning Angles

A frequency- and pattern-reconfigurable $1\times4$ array is analyzed and designed, which consists of a reconfigurable feed network, 12 rectangular parasitic patches, and four octagonal patch antennas. Characteristic mode analysis (CMA) is used to study the radiation characteristics of the proposed element antenna. By changing the ON–OFF states of 18 p-i-n diodes loaded in the feed network, different combinations of the initial current phase are obtained to realize the reconfiguration of five radiation states. By loading varactor diodes and parasitic patches, frequency reconfigurability is achieved. The measured result shows that the array pattern can be discretely switched in the directions of 0°, ±15°, ±25°, ±30°, and ±55°. The tunable overlapped −10-dB impedance bandwidth is 3.54–4.46 GHz for the five radiation patterns. The maximum gain reaches 7.67 dBi and the overlapped relative bandwidth of five radiation states is more than 22%.