Design and Analysis of Metamaterial-Based SWB-MIMO Antenna

Abstract

The design and analysis of a four-port multi-input multi-output (MIMO) super wideband antenna (SWB) with a metamaterial superstrate are proposed. Initially, a single antenna is constructed with a hexagonal radiator loaded with dodecagon slots along with a slotted partial ground. An impedance bandwidth of 4.1–14.7 GHz is achieved by using symmetric coplanar waveguide feeding technique and three iterations of dodecagon slot-loaded radiating element. The design is extended to a 2 × 2 MIMO antenna with dimensions 50 × 50 × 1.6 mm3. The four symmetrical SWB antennas are placed orthogonally to each other at four corners of a square-shaped FR4 substrate. A metamaterial superstrate is used above the four-port antenna to increase the antenna’s performance characteristics. A 7 × 7 array of rectangular metamaterial unit cells acts as a building block for the metamaterial superstrate to improve impedance matching, enhance isolation between the elements, and boost the antenna’s gain. The metamaterial unit cells are made up of three rectangular rings that are put on top of a 1.6 mm thick FR4 substrate. With a mutual coupling of (>15 dB), the antenna achieved S11 < −10 dB for an impedance bandwidth of 11 GHz. The gain enhancement of up to 1.73 dB is obtained in C and X bands using metamaterial superstrate. The antenna characteristics mainly peak gain, return loss, bandwidth, and isolation are examined. The simulated results affirm a decent deal with experimental results.