Multi-slot Antennas Excited by Novel Dual-stub Loaded Microstrip Lines for 4G/5G Bands

Abstract

This paper presents a low-profile, stub-loaded multi-slot antenna that operates across 850 MHz to 4500 MHz. Remarkably, the new design meets the call of covering wideband frequencies used by many 4G and 5G New Radio bands from UHF to C bands. The antenna consists of two wide slots on the ground plane. Each slot comprises a straight segment connected to a larger circular slot. A novel microstrip feed line loaded with dual circular stubs excites the multi-slot antenna. The slots and feed lines are printed on each side of the dielectric substrate. This novel design offers pattern diversion capacity based on port excitation. Two prototypes were fabricated and tested to verify multiple simulation results including bandwidth, isolation, and group delays. A close consistency of measured and simulated results validates the design. Concurrently, good isolation between ports and nearly omnidirectional gain patterns are observed over the band. Further, the form factor of the proposed antenna makes it a suitable solution for modern 4G and 5G handheld devices.