Investigation of Stacked Balanced-Fed Patch Antenna for Millimeter-Wave Application

A stacked patch antenna with balanced feed operating in millimeter-wave band is proposed in this paper. Initially, a single balanced-fed patch antenna is designed in three layers. Simulation results show that the proposed antenna enhances the cross-polarization and the radiation gain of the conventional aperture coupled patch antenna. A maximum gain of 6.8 dBi is achieved with a bandwidth of 2 GHz around 26 GHz. The stacked patch antenna was fabricated using 0.65 mm AR1000 and 0.787 mm RO5880 substrates. Measurement results of return loss agreed with the simulations and showed wide bandwidth, which is required for future 5G communication terminals. To further increase the gain, we propose an integrated 8-element antenna array based on an 8-way Wilkinson power divider. The proposed design achieves a maximum gain of 14.1 dBi at 26 GHz with greatly reduced grating lobes and cross-polarization. The proposed antenna array represents a potential solution for the emerging 5G wireless applications.