Design of Quad-Port MIMO/Diversity Antenna with Triple-Band Elimination Characteristics for Super-Wideband Applications

Abstract

A compact, low-profile, coplanar waveguide (CPW)-fed quad-port multiple-input–multiple-output (MIMO)/diversity antenna with triple band-notched (Wi-MAX, WLAN, and X-band) characteristics is proposed for super-wideband (SWB) applications. The proposed design contains four similar truncated–semi-elliptical–self-complementary (TSESC) radiating patches, which are excited through tapered CPW feed lines. A complementary slot matching the radiating patch is introduced in the ground plane of the truncated semi-elliptical antenna element to obtain SWB. The designed MIMO/diversity antenna displays a bandwidth ratio of 31:1 and impedance bandwidth (|S11| ≤ − 10 dB) of 1.3–40 GHz. In addition, a complementary split-ring resonator (CSRR) is implanted in the resonating patch to eliminate WLAN (5.5 GHz) and X-band (8.5 GHz) signals from SWB. Further, an L-shaped slit is used to remove Wi-MAX (3.5 GHz) band interferences. The MIMO antenna prototype is fabricated, and a good agreement is achieved between the simulated and experimental outcomes.

Design and Implementation of Quad-Element Super-Wideband MIMO Antenna for IoT Applications

“…A MIMO antenna consisted of four spade-shaped radiators and a windmillshaped decoupling element was presented [25], where an elliptical slot was etched on the antenna element to improve its radiation performance. A MIMO antenna consisted of four semi-elliptical resonating elements was reported in [26], where triple notched bands were achieved by etching an L-shaped element and a complementary split-ring resonator (CSRR) on the patch. However, the SWB MIMO antenna configurations reported so far mainly comprised of two antenna elements [21][22][23][24] and one or two notched bands [24].…”

“…However, the SWB MIMO antenna configurations reported so far mainly comprised of two antenna elements [21][22][23][24] and one or two notched bands [24]. A few SWB antenna designs were presented with four resonating elements [25][26] and triple notchedband features [26], but their large sizes may limit their applications in compact IoT modules. Also, the ground of the antenna elements in [21], [23], [25] are not interconnected, therefore, these antennas might not be used for practical MIMO applications.…”

Ultra-Compact Reconfigurable Band Reject UWB MIMO Antenna with Four Radiators

“…Conversely, on demand rejection using active switches such as PIN diodes, RF microelectromechanical system (MEMS) switches, and optical switches have also been proposed in the literature [19][20][21][22][23][24]. However, the demonstrations of reconfiguration mechanism/on-demand band rejection has only been performed on a single or at most of two elements antenna system [22].…”

“…The use of disconnected ground planes provides fabrication simplicity and mitigate coupling issues in such a closely packed configuration. On the other hand, the incorporation of decoupling structures may replace separate ground planes requirement but at the cost of increased hardware complexity and fabrication challenges [23,24].…”

Design of Quad-Port Ultra-Wideband Multiple-Input-Multiple-Output Antenna with Wide Axial-Ratio Bandwidth

“…Recently, the attention of the researchers has been shifted to multiple-input-multiple-output (MIMO) antennas as they help in reducing multipath fading and achieving higher range, more reliability, and high data rate, without increasing transmitted power or bandwidth [5]. Several individual elements are combined together, with enough inter-element isolation, to obtain a high-performance MIMO/diversity antenna [6]. Due to space limitations in the wireless devices, there is a requirement for small-sized MIMO antenna configurations, which may result in a larger mutual coupling effect and subsequent degradation in the performance of the system [7].…”