A Compact Integrated Microwave and Millimeter Wave Antenna for 5G Applications

Abstract

This letter presents the design of a compact integrated antenna operating across both FR1 and FR2 frequency ranges for 5G applications. The proposed structure, with overall dimensions of 0.58λ_G × 0.66λ_G × 0.01λ_G, employs a common aperture shared by a slot antenna and a patch antenna. In the microwave band, the slot-based radiator exhibits a bidirectional radiation pattern, which is well suited for wide-area and orientation-independent connectivity in 5G IoT and sub-6 GHz communications. At millimeter wave frequencies, the patch radiator generates a broadside radiation pattern with moderate gain, enabling high-data-rate directional links such as device-to-device communication and vehicular communications. The proposed dual-band antenna achieves peak gains of 5.6 dBi in the microwave band and approximately 10.2 dBi in the millimeter wave band. The antenna provides wide fractional impedance bandwidths of 74% (3.3–7.2 GHz) and 23.8% (24–30.5 GHz), effectively covering several key 5G bands. Owing to its novel integrated structure, an isolation better than 30 dB is achieved in both bands. Furthermore, frequency-dependent beam scanning is observed in both operating bands. A prototype was fabricated, and the measured results show close agreement with simulations.