Wideband MIMO antenna with small ground clearance for mobile terminals

Abstract

In this study, a compact planar multiple‐input‐multiple‐output (MIMO) antenna is presented for mobile terminal applications. Various dual‐element configurations are studied using the theory of characteristic modes. The reason of port isolation is explained from the view of modal weighting coefficients. It is found that by arranging the two elements at the top and bottom sides of the board and placing the feed ports at the corners of the board, not only the bandwidth is enhanced but also the port isolation is improved. To further broaden the bandwidth, three branches are well cooperated to provide three λ/4 modes. The optimised no‐ground region (i.e. the ground clearance) of each element only occupies an area of 5 × 30 mm2. The measured bandwidth can cover the 1710–2690 MHz band with the criterion of −10 dB reflection coefficient. The measured port isolation achieves 19 dB without using any decoupling structure. The efficiency is >60% in the entire band. In addition, the user effect on MIMO antenna performance is evaluated.

Techniques for Compact Planar MIMO Antennas

“…The CMA permits the researcher to know the antenna performance at the initial stage without considering the specific excitations so that the user can have an insight into the radiation essence, which is extensively used in the application of mobile handset antenna where the large metal chassis exists [116]. And the MIMO antennas are also extensively investigated for the mobile terminal application, there are a lot of works using the CMA [47,117,118].…”

“…Techniques for Compact Planar MIMO Antennas DOI: http://dx.doi.org/10.5772/intechopen.112040 excited to get the low SAR, and the isolation of 16 dB is achieved. On the contrary, the CMA is implemented on both the ground plane and the antenna in [117], but only on the chassis ground plane in [118]. The first four modes of [118] are shown in Figure 18.…”

“…On the contrary, the CMA is implemented on both the ground plane and the antenna in [117], but only on the chassis ground plane in [118]. The first four modes of [118] are shown in Figure 18. With the help of the current distributions, the antennas are put intensityweak position of the corners for the MIMO antenna design.…”

Design and Analysis of Wideband Flexible Self-Isolating MIMO Antennas for Sub-6 GHz 5G and WLAN Smartphone Terminals

“…Recently, several researchers have carried out intensive work on MIMO antennas for mobile phones [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. However, the space limitation in mobile phones brings challenges in integrating a greater number of antennas with a good value of isolation and lower ECC.…”

“…However, the space limitation in mobile phones brings challenges in integrating a greater number of antennas with a good value of isolation and lower ECC. Single-port [9], dual-port [10][11][12][13][14][15][16], and quad-port [17][18][19][20][21][22][23][24][25] MIMO antennas are proposed for smartphone terminals by researchers. The single-port antenna proposed in [9] resonates at a dual-frequency band; however, the efficiency of the antenna is much lower, and it does not cover the 5G band.…”