Search

To meet the demands of the new frequency bands and the $4\times 4$ multiple-input multiple-output (MIMO) specification brought by fifth generation (5G), a triple-band microstrip patch antenna and its four-antenna module are proposed. Based on the half-mode microstrip patch, the first three modes of TM1/2,0, TM1/2,1, and TM3/2,0 that can be independently tuned are engineered to cover the three Chinese 5G bands (N41/N78/N79). The proposed triple-band microstrip patch antenna with the volume of $33.5\times 32.5\times 4$ mm3 shows the −6 dB frequency bands of 2.47–2.75 GHz, 3.39–3.60 GHz, and 4.69–5.10 GHz, which makes a nice compromise between antenna volume and impedance bandwidths. Four such patches are arranged in a sequentially rotated style to constitute the triple-band four-antenna module, which is with the volume of $71\times 71\times 4$ mm3. Measured results of the module show high performance. The reflection coefficients of the four elements are almost identical: the bandwidths are 2.50–2.75 GHz, 3.41–3.62 GHz, and 4.68–5.01 GHz; all the isolations are better than −13.3 dB; the average total efficiencies of the four elements are between −1.41 and −1.11 dB, −2.45 and −2.10 dB, and −1.81 and −1.53 dB for N41, N78, and N79, respectively; and all the envelope correlation coefficients (ECCs) are lower than 0.07. [ABSTRACT FROM AUTHOR]

This article presents a dual-band and dual-polarized microstrip antenna array with broadside beam scanning ability for millimeter-wave applications. Within a compact multilayer structure, wide bandwidth and high port isolation are achieved by using double-layer gridded patches with three groups of metallic via-fences. For beam scanning purpose, a prototype of $2 \times 2$ array is designed, fabricated, and tested. The experimental results agree well with the simulations. For both orthogonal polarizations, the −10 dB bandwidth covers 23.3–31.7 and 42.5–46.5 GHz with average gains of 12 and 13.1 dBi, respectively. A 3 dB beam scanning angle from −51° to 43° at 27 GHz and −28° to 30° at 45 GHz is obtained. The proposed array provides dual-band and wideband properties for dual orthogonal polarizations with competitive beam steering range and compact dimensions, as a feasible solution for fifth-generation (5G) millimeter-wave mobile communications. [ABSTRACT FROM AUTHOR]

The huge proliferation of the antenna number brought by 5G greatly increases the pressure of the bezels of the 5G terminals. To release the pressure, planar four-antenna module with miniaturization and wideband performance that can be implemented on the back cover is proposed in this article. Four identical dual-mode PIFAs are arranged in a sequentially rotated style and the whole antenna appears in a circular shape. Each antenna element is a slotted quasi-quarter circle with one inner edge shorted and the other two edges left open, and it is coupled fed by an L-shaped microstrip line. A cross line that connects all the four elements together is used to improve the isolation of the neighboring elements. The four-antenna module covering N77 is with the diameter of 30.6 mm and height of 2 mm. The measured results show that for all the four antenna elements, the −6 dB impedance bandwidths cover 3.3–4.2 GHz, all the isolations are better than 9.7 dB, the average total efficiencies are between 36% and 40%, and envelope correlation coefficients (ECCs) are lower than 0.5. To the best of the authors’ knowledge, this is the smallest four-antenna module covering 3.3–4.2 GHz. [ABSTRACT FROM AUTHOR]

This article proposes a novel design of the dual-band antenna pair. Starting from the single-band antenna pair composed of T-shaped monopole and T-shaped slot that are intersected with each other, orthogonal T-monopole and odd-symmetrical slot modes are excited. By adding symmetrical low-pass high-stop filters into the horizontal stub of the T-monopole and high-pass low-stop filters into the gap of the T-slot, an extra mode is introduced for each antenna, producing dual-band operation. Impedance bandwidths and radiation efficiencies of both bands can be adjusted flexibly using the filters. A detailed design guideline is given. The dual-band antenna pair operating at partial N78 (p-N78, 3.4~3.6 GHz) and partial N79 (p-N79, 4.8~4.9 GHz) is with a footprint of $15\times 6$ mm2. The measured results show that the average efficiencies are both −3.4 dB at p-N78/p-N79 for the odd-symmetrical slot and −2.8 dB/−3.7 dB at p-N78/p-N79 for the T-monopole, isolations are better than −16.8 dB at p-N78 and −11.8 dB at p-N79, and ECCs are lower than 0.1 at p-N78 and 0.2 at p-N79. The proposed dual-band antenna pair exhibits great potential to be applied in the fifth-generation (5G) multiple-input multiple-output (MIMO) terminal. [ABSTRACT FROM AUTHOR]