High Efficiency Wide‐Beam Antenna Array With H‐Plane Beamwidth Enlargement and Filtering Properties for Millimeter‐Wave Applications

ABSTRACT This manuscript presents a 1 × 4 wide‐beam patch antenna array that is serially fed by a double‐side substrate integrated suspended line (DSISL) for millimeter‐wave applications. A novel wide‐beam method with beam enlargement only in H‐plane is proposed and very suitable for the serially‐fed array. Two vertical patches in the special shape of inverted “T” are installed on both sides of radiation patch of antenna element to broaden the beamwidth only in H‐plane. Antenna element with wide beamwidth only in H‐plane can help the antenna array to obtain wide beamwidth in H‐plane while achieve a lower side lobe level (SLL) in E‐plane. In addition, benefiting from the features of low loss and good shielding effect, a DSISL is used to realize high efficiency property. Besides, the proposed antenna array is fed by the way of series with an open end to obtain filtering response. There are no extra filtering circuits so the antenna efficiency can be improved further. For demonstration, the proposed 1 × 4 antenna array working at 24 GHz is fabricated and measured. The measured results shows that the proposed antenna works from 23.7 to 24.4 GHz with the beamwidth of 140° in H‐plane, total efficiency of 82.6%, and suppression level of 22.3 dB. Based on its features of wide beamwidth while keeping high efficiency and good filtering performances, the proposed antenna has great potential in wide‐coverage mm‐wave application.