Design of a Low-Sidelobe Millimeter-Wave Microstrip Array Antenna

This paper presents the design of a X-band patch antenna with low sidelobe. In order to achieve a wideband operation, the microstrip patch antenna with slot coupling feed is adopted. The two-dimensional optimization of excitation amplitude and element displacement is proposed to achieve the low sidelobe radiation. And the 6 X 8 antenna array as a whole is designed using the a multi-layer printed board. The antenna impedance bandwidth is greater than 20%, the array gain is higher than 21.5 dBi in the operating frequency band 9.15GHz to 10.15GHz, the side lobe level of the antenna H-plane is less than - 17.25 dB, the E-plane side lobe level is less than -14.28 dB, and the front-to-back ratio is less than -30 dB.