Low-Profile and Miniaturized Dual-Band Microstrip Patch Antenna for 5G Mobile Terminals

This communication proposes a novel method to design low-profile and miniaturized dual-band microstrip patch antenna for 5G mobile terminals. Magnetic coupling is introduced to excite the parasitic patch that aims to improve the impedance and efficiency bandwidths simultaneously. Magnetic coupling is applied to the first two modes of the half-mode patch, i.e., TM _0.5,0 and TM _0.5,1 modes, and the effects of the parasitic patch on both modes obey the same physical regulation. As a result, dual-band operation with enhanced bandwidths under a low profile is acquired. Slots are etched off for size reduction. The proposed dual-band patch antenna constructed by a pair of back-to-back slotted half-mode patches operating at partial 5G band N78 (3.4–3.6 GHz) and partial N79 (4.8–5.0 GHz) is with a profile of 1 mm ( $0.012\lambda _{\mathrm {L}}$ ) and footprint of $31.35\times18$ mm ² ( $0.36\lambda _{\mathrm {L}} \times 0.21\lambda _{\mathrm {L}}$ ). Measured results show that the −6 dB impedance bandwidths are 9.1% (3.46–3.79 GHz) at lower band and 4.3% (4.97–5.19 GHz) at higher, and the average efficiencies are −1.3 dB (74.1%) and −3.2 dB (47.9%). To the best of the authors' knowledge, the proposed dual-band patch antenna is with superior performance to most of the reported planar dual-band antennas considering bandwidth and volume.