Design of a dual‐polarised antenna with high isolation and a metallic cube for beyond 4G small base station applications

Abstract

Dual polarised antenna with high isolation for small base‐station applications is proposed. The proposed antenna is composed of two metallic trapezoidal dipole elements, two metallic feed plates, a dielectric substrate, a metallic cube and a radome. The measured −10 dB impedance bandwidth is 2.4 GHz to 2.8 GHz in Port‐1 and 2.5 GHz to 3 GHz in Port‐2. The proposed antenna has an isolation of >45 dB at the centre frequency. The measured average antenna gain is 7.5 dBi, and the cross polarisations are all <30 dB below the co‐polarisation value.

An isolation-enhanced quad-element antenna using suspended solid wires for LTE small-cell base stations

“…An LTE small-cell base station requires its antenna having multiple elements that cover full LTE frequency bands, including an upper LTE band (LTE1700/1900/2100/2600, 1710-2690 MHz) and a lower LTE band (LTE700/850/900, 698-960 MHz). However, to date the development of MIMO antennas for this application is limited by insufficient number of multifrequency bands, as the literature focuses on either the upper LTE band [Zhai et al, 2015;Arya et al, 2015;Lee et al, 2015;Jin and Du, 2015;Lee et al, 2014;Cui et al, 2014;Zhai et al, 2014;Quan and Li, 2013;Luk and Wu, 2012;Wu and Luk, 2009;Mak et al, 2007] or lower LTE band alone [Chen and Chang, 2016;Yan and Bernhard, 2012]. No research findings are yet available concerning MIMO antenna design meeting the full LTE specification for compact base stations.…”

Design of a four‐element multiple‐input–multiple‐output antenna for compact long‐term evolution small‐cell base stations

“…Although a LTE MIMO antenna developed in a compact volume is a fundamental issue, the design task is very challenging because there is a contradiction between a compact antenna size and multiple unit elements operating in lower LTE frequency bands such as 700 MHz. In fact, earlier attempts at developing MIMO antennas for compact base stations have limited success in the LTE700 frequency band [3][4][5][6][7][8][9][10][11][12][13][14][15]. The antenna size, operational frequencies, and the number of unit elements of these recent studies are summarised in Table 1.…”

“…The antenna size, operational frequencies, and the number of unit elements of these recent studies are summarised in Table 1. As can be seen that there is very limited study focusing on LTE700/850/900; most of the literature concerning MIMO base-station antennas aims at higher frequency bands, the lowest operational frequency of which is larger than 1.7 GHz [3][4][5][6][7][8][9][10][11][12][13]. However, a MIMO base-station antenna operated in LTE700/850/900 is very urgent and still critically lacking.…”

“…To accomplish the design task, three challenging issues need to be resolved. First, in contrast to most of the literature targeting at LTE1700/1900/2100/ 2600 [3][4][5][6][7][8][9][10][11][12][13], this work aims at the bandwidth requirement of LTE700/850/900; accordingly, the unit antenna element not only has a larger electrical size, but it also encounters more difficulty to have a wide impedance bandwidth. In this work, a monopole antenna with a sleeve attached to each side is designed to serve the unit element.…”

Design of a dual‐polarised small base station antenna with a metallic isolator for micro‐cell systems

“…The miniaturisation of a BS antenna is also of particular importance. We created a small BS antenna with a metallic cube [1][2][3][4], where the BS antenna is mounted inside the metallic cube, and has high gain and isolation. In [5][6][7][8][9][10][11], a dual-polarised antenna using electric and magnetic fields is used.…”