Broadband slot arrays with wide H‐plane beamwidth

Designs of 1 × 4 vertically polarized arrays with wide beamwidths are described. The array is composed of two pairs of monopole slot antennas, and each pair is excited with a differential feed scheme to reduce cross polarization. In addition, a rectangular metallic box is introduced as a reflector of the array to generate different beamwidths and improve front‐to‐back ratios. From the simulated results, it is found that by tuning the dimensions of the metallic box, the H‐plane half‐power beamwidth of the array can be varied between 90° and 180°. For each beamwidth case, the 10dB‐return‐loss bandwidth (BW) of the array can cover the band from 1.7 to 2.7 GHz; moreover, a cross polarization of lower than −20 dB, a front‐to‐back ratio of higher than 15 dB, and a beamwidth variation of <10° are also realized within the impedance BW. An experiment is also carried out to validate the simulation.