Design of A Low-profile and Wideband Glass Antenna for Millimeter-wave Applications

A new low-profile and wideband glass patch antenna with U-shaped microstrip feeding structure for millimeter-wave applications is proposed and studied. Combined with the field distribution of patch antenna, a short-circuited U-shaped microstrip feeding line is put underneath a rectangular patch to excite its fundamental mode. By using a common ground plane between the feeding line and radiation patch, the antenna achieves a wide bandwidth (VSWR <2) of 26.0% ($\mathbf{3 0. 6 0 - 3 9. 7 4}$ GHz) with a low profile of 0.0620 (the operating wavelength of the central frequency in the free space). The maximal broadside realized gain reaches 6.81 dBi with a small variation of 0.93 dB within the impedance bandwidth. The proposed glass patch antenna with a wide bandwidth and low cost can be applied in antenna-in-package (AiP) for millimeter-wave applications.