Dual-Band Dual-Polarized Microstrip Patch Antenna With Parasitic Elements for 5G Antenna-in-Package Design at Millimeter-Wave Frequencies

Antenna implementations at millimeter-wave (mmW) frequencies on printed circuit boards (PCBs) suffer a high dielectric loss due to long metal-feeding microstrips. Antenna-in-packages (AiPs) are practical solutions to shorten the lengths for power loss reduction. In addition, 28 and 39 GHz bands have been designated for the fifth generation (5G) of mobile communications. An active AiP covering these two bands is developed to provide dual-band and dual-pol radiation based on the microstrip patch structure with parasitic elements to produce a second resonance. The large cross-polarization due to the mutual coupling between adjacent ports of dual-pol is further suppressed by considering an image relation of elemental antennas’ orientations in the array composition. Numerical full-wave simulations and measurements over an antenna prototype are both shown to demonstrate the radiation where active transceiver modules were integrated. The examinations validate the feasibility of this AiP technique for 5G user equipment applications.