A Millimeter-Wave High-Gain Magneto-Electric Dipole Antenna Array with Pillbox Corporate Feed Network

This paper presents a high-gain antenna array with the use of magneto-electric (ME) dipole antenna elements operating at millimeter-wave frequencies. The proposed array achieves wide bandwidth, high gain and low sidelobe level (SLL) in its planar structure. A highly-efficient power divider consisting of pillbox transition and corporate feed network is introduced to produce equal phase but non-uniform power distributions to all array elements such that it can be for suppressing the SLL of the array. The radiating element is constituted by a cavity-backed slot-coupled ME dipole, which offers a wide impedance bandwidth and a stable radiation pattern. A prototype of the antenna array is fabricated and measured to verify the proposed design. The array achieves an impedance bandwidth of 20.8% (for the reflection coefficient ≤ -10 dB) covering the frequency range from 54.2 to 66.8 GHz. The average gain of the array is 28.5 dBi in its operating bandwidth, with a peak gain of 29.6 dBi at 65 GHz. The lowest E-plane SLL level over the entire bandwidth is -18 dB. This proposed antenna array has potential applications in long-distance millimeter-wave communications due to its merits of wideband, high gain, and low SLL features.