This letter presents a center-feed high-gain and high-efficiency 4 × 4-element slot array antenna in the 60 GHz band. The antenna feed network is designed using only a single-layered square quad-ridge cavity structure, which is excited through a rectangular slot that has the same size as that of a standard WR-15 rectangular waveguide. The proposed antenna avoids any conventional power dividers in the feed network, which reduces the complexity of the design and fabrication process. To enhance the operating bandwidth of the antenna and prevent the grating lobes effects, a stepped design is used for each radiating slots of the array. Furthermore, the overall radiating aperture of the antenna is equipped with a dielectric layer, which decreases the mutual coupling among array elements. As a result, a broad bandwidth antenna with high efficiency and low sidelobes in both E- and H-planes is developed over the 60 GHz band. The antenna has been fabricated and tested. Measurement results show an operating bandwidth of 11.6% from 57.7 to 64.7 GHz. A gain of more than 23 dBi, sidelobes of less than −15.2 dB, and an antenna efficiency of better than 60% are achieved.

中文翻译：

---

60GHz 波导馈电空腔阵列天线，采用多级隙缝孔径

这封信展示了 60 GHz 频段的中心馈电高增益和高效率 4 × 4 单元缝隙阵列天线。天线馈电网络仅采用单层方形四脊腔结构设计，通过与标准 WR-15 矩形波导尺寸相同的矩形缝隙进行激励。所提出的天线避免了馈电网络中的任何传统功率分配器，从而降低了设计和制造过程的复杂性。为了提高天线的工作带宽，防止栅瓣效应，阵列的每个辐射槽采用阶梯式设计。此外，天线的整体辐射孔径设有介电层，减少了阵元之间的相互耦合。因此，在 60 GHz 频带上开发了一种在 E 和 H 平面中具有高效率和低旁瓣的宽带宽天线。天线已经制作完成并经过测试。测量结果显示从 57.7 到 64.7 GHz 的工作带宽为 11.6%。实现了大于 23 dBi 的增益、小于 -15.2 dB 的旁瓣和优于 60% 的天线效率。