Broadband 120 GHz L-Probe Differential Feed Dual-Polarized Patch Antenna With Soft Surface

This article presents a broadband 120 GHz L-probe differential feed dual-polarized patch antenna with a soft surface. The impedance bandwidth is widened with additional resonance points by applying an L-probe feeding topology. Using differential feeding and soft surface, the overall radiation performance including the radiation pattern, cross-polarization, and isolation is improved for a wide bandwidth covering the targeted band, and the analysis of each structure is described in this article. The measured S11 bandwidth, peak gain, 3 dB gain bandwidth, and isolation are 28.3%, 9.8 dBi, 26.4%, and 28.5 dB, respectively. The proposed dual-polarized antenna reveals the widest S
₁₁
bandwidth, with a 3 dB gain when compared with the previously reported millimeter and sub-THz dual-polarized antennas. Moreover, to the best of the authors’ knowledge, the proposed dual-polarized antenna is demonstrated at the highest frequency compared with the previously reported dual-polarized antennas.