Compact Aperture-Shared Tri-Frequency Antenna Based on Partial Structure Reutilization for Millimeter-Wave and Sub-6 GHz Applications

This article proposes a compact aperture-shared antenna that covers multiple commonly used frequency bands, utilizing partial structure reutilization techniques. The proposed antenna achieves a high space utilization, integrating one microwave (MW) magnetoelectric dipole (MED) antenna and two different millimeter-wave (MMW) rectangular open-ended waveguide arrays. Meanwhile, excellent beam scanning performance in the MMW band is ensured by reusing vertical grounded walls of the MW MED antenna, for it effectively suppresses mutual coupling and surface wave transmission. To verify the rationality and feasibility, a prototype is fabricated and measured. The MW antenna covering both the n79 band (4.8–5 GHz) and the vehicle-to-vehicle band (5.855–5.925 GHz) exhibits a relative bandwidth of 36.3% (4.63–6.68 GHz), with a peak gain of 7.67 dBi. Simultaneously, the MMW array covers n257 and n260 bands. The first array ranges from 26.4 to 29.6 GHz (11.4%), with a peak gain of 9.46 dBi and supports ±50° beam scanning. The second array ranges from 36.6 to 40.5 GHz (10.1%), with a peak gain of 9.61 dBi, and supports ±30° beam scanning. Considering significant benefits such as compact size, high space utilization, broadband feature in MW band, and stable beam scanning performance in MMW bands, the proposed tri-frequency aperture-shared antenna will be a good choice for 5G communication applications.