A Millimeter-Wave Resonant Cavity Antenna with High Gain and Low Sidelobe Level

This paper presents a Millimeter-Wave (mm-wave) resonat cavity (RC) structure with high gain and low sidelobe level (SLL). It consists of a 5×5 dipole antenna array as a main radiator fed by a series feeding network. The network is designed based on the Chebyshev distribution to decrease the SLL. A partially reflective surface (PRS) is designed and placed above the dipole array to improve the RC radiation characteristics. All dipoles arranged in a separated row are connected by a series network with Chebyshev distribution weights. A vertically-placed series feeding network is applied to feed all five rows of the dipole array and is enclosed by a metallic cavity to decrease the undesired backward radiations resulting from the vertical feeding line. It is observed that the sidelobe level can be reduced to -32 dB and -27 dB at E-plane and H-plane, respectively. Also, a high gain of 22 dBi is achieved at 28 GHz.